What is blood spot testing?

Blood spot testing is a blood screening test which allows your child to be tested for 1 of 9 rare conditions. These conditions are:

• Sickle cell disease.
• Cystic fibrosis.
• Congenital hypothyroidism.

Or these inherited metabolic diseases: 

• Phenylketonuria (PKU).
• Medium-chain acyl-CoA dehydrogenase deficiency (MCADD).
• Maple syrup urine disease (MSUD).
• Isovaleric acidaemia (IVA).
• Glutaric aciduria type 1 (GA1).
• Homocystinuria (pyridoxine unresponsive) (HCU).

Completing this blood spot test, allows these conditions to be identified and treated, improving your child’s health.

Why does your child have to have a blood spot test?

When a child is born in the UK, blood spot testing is routinely done to rule out rare conditions in the first few weeks after birth. Because your child was born in another country, we must complete this test here. This can only be done if your child is under the age of 1.

What can you expect from your appointment?

One of our nurses will bring you and your child into one of our treatment rooms and will discuss the procedure, talking you through any questions you may have.

Your child will then have the blood spot carried out. This involves a small heel prick using a lancet (small needle) to get small drops of blood which are then applied to a card as shown in the picture. Your child may cry or become distressed when this is done, so reassurance and lots of cuddles will help.

Once the sample has been taken, this will be sent off to the lab to be processed. The results usually take a few weeks and you will be sent a letter if any of your child’s results are abnormal. If you have any questions or queries after your appointment you can contact us. Our details are on the back of this leaflet.

For further information speak to your GP or contact one of our nursing team at the Paediatric Outpatients Department.

Sources of further information

Newborn blood spot test - NHS

Blood spot - GOV.UK

Information in different langauges

Newborn blood spot screening (English and translations) | HSC Public Health Agency

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003748

Introduction

It is important your child is prepared for their blood test as they may have questions, fears, and anxieties. This page will help you explain what will happen during their short visit to the blood clinic.

How is a blood test done?

• Before your child has their blood test we can use a spray that numbs the skin. It works quickly and doesn’t last very long so the bloods will be taken immediately after the child’s skin has been sprayed.
• The nurse will squeeze your child's arm or wrist - this makes the vein fill up with blood and makes it easier for the blood sample to be taken.
• A butterfly needle (small needle) is then inserted into the vein - the needle is connected to a syringe and the blood taken out.
• When the required amount of blood is taken, the needle is removed. The nurse presses on the small wound with cotton wool for a few minutes to stop the bleeding and prevent bruising. A sticky plaster is then put on.
• While the nurse puts the blood into bottles, your child will be encouraged to choose a sticker. This can help them feel they have achieved the goal of having blood taken and to reward them for their bravery.

Why are there so many bottles?

Blood can be tested for many different things. Your child’s doctor will request which tests they want us to take. Different blood bottles are used for different tests - this is why you may see your child’s blood added to bottles of different sizes and colours.

What can I do to help? 

• Keeping your child hydrated reduces the risk of their blood pressure dropping. A drop in blood pressure is the leading cause of fainting and dizziness during blood tests. Being hydrated makes their veins plumper and more visible making it easier for the phlebotomist to find a vein.
• Keep warm. If it is winter or cold outside this can make the veins hide and make it harder to collect a sample. Your child should wear gloves or suitably warm clothing for the appointment.
• If you have been told by your clinician your child should fast before your test (typically for 12 hours) then please bring something for your child to have afterwards. Sugary/sweet snacks are ideal.

Are there any complications?

• Sometimes a bruise develops where the needle was put in. This is much less likely to happen if you press over the site with cotton wool for a few minutes, keeping your child's arm straight. The nurse will do this for you.
• Rarely, some people feel faint during a blood test. Your child (or yourself) will be encouraged to lie down if this happens to prevent fainting.
• Occasionally it can be difficult to find a vein to take the blood from and it may take more than one attempt to get a sample.

When will we get the results?

Results will be passed onto the clinician who requested the tests. They will usually wait until all the results are ready to inform you of the results. Some tests will take longer to process than others – for example, genetic screening can take between 8-12 weeks to be ready.

For further information

Speak to your community midwife, health visitor, GP or ask the nurse you will see in the paediatric outpatient department.

Sources of further information

Blood tests - NHS

Fainting - NHS

Bumps & Bruising - Symptoms & Treatment | St John Ambulance

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003753

Why do I need to eat less phosphate?

Phosphate (also known as phosphorus) is found in a variety of foods. It is needed for healthy bones. The kidneys help control the amount of phosphate in the blood and when they are not working properly, the level of phosphate in the blood can rise. 

The normal range for blood phosphate is between 0.8mmol/l and 1.5mmol/l. 

High levels of phosphate can cause:

• Hardening of blood vessels.
• Damage to your heart.
• Weak bones.
• Aching joints.
• Itchy skin.
• Sore eyes.

How can I control my phosphate levels?

You can help to lower phosphate levels in your blood by reducing foods that are high in phosphate. If your phosphate levels stay high you may be prescribed tablets called phosphate binders. These are taken with food to reduce the amount of phosphate absorbed from food. The dietitian can give you more information on how and when to take these tablets if they are prescribed.

How can I eat less phosphate?

Eating less processed food

Phosphate additives

How do I eat fewer phosphate additives?

You will always see the name of phosphate additives, or their E numbers listed on the ingredients labels where they have been used. Look out for additives with ‘phos’ in their name as these will contain phosphate. You may be able to swap to a different brand without additives.

To help you avoid phosphate additives, here are some examples of food labels showing how phosphate additives are listed on a food label.

Sausages

Cake

If a food contains phosphate additives try checking other brands or similar alternatives to find one without.

Eating moderate amounts of dairy foods

Choosing foods lower in phosphate

Higher phosphate foods to limit

Useful websites

Next steps: what I can do to help control my phosphate

It can be helpful to write down what you can do to help control your phosphate. 

Contact your dietitian if you need further help. 

© North Bristol NHS Trust. This edition published August 2023. Review due August 2026. NBT003420.

Please read this information carefully before coming in for your overnight polysomnography.

What is a polysomnography?

Polysomnography (also known as sleep studies) is a test used to diagnose sleep disorders. Electrodes and sensors are placed on the body and head to record different information that allow your sleep to be studied in detail for 1 or 2 nights. A video recording is taken during the study to help diagnose your sleep problem.

Why do a polysomnography?

The main reason is to try to classify (work out exactly) the problem you are having with your sleep so that the referring doctors can treat it more effectively.

What happens during the test?

Small discs (electrodes) are applied to your scalp, around your eyes, and under your chin. These will be attached with special glue, so they do not fall off in your sleep.

2 belts will be placed around your chest and abdomen that measure your breathing, with additional boxes attached where the wires are connected. A nasal cannula will rest in your nose to also measure breathing. 2 sticky pads will be placed: 1 on your shoulder and 1 on your hip to detect your heart rate. A pulse oximeter will be placed on your finger to detect blood oxygen saturation. A movement sensor is placed on your arm and 1 on each of your legs to detect any movements in your sleep.

The equipment will stay in place until the end of the test, and it is removed by a neurophysiologist.

The night-time recording is started as close to your normal sleep time as possible. Wake time is usually before breakfast at around 08:30.

It may be necessary to do a Multiple Sleep Latency Test (MSLT). This involves settling down to sleep at specific sections of the day. These periods are about 20-40 minutes and are about 2 hours apart. You will be woken up at the appropriate time by your neurophysiologist.

Preparation for the test 

Follow these instructions carefully for the MSLT

• Do not consume any alcohol, coffee, or stimulating drugs (medication) the night before or morning of the test.
• Stop smoking at least 30 minutes before each test.
• Do not doze off in-between the test sessions.

General preparation for polysomnography

• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You must arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• You will be set up in the clothes you sleep in, and won’t be able to change during the test. Please make sure you bring suitable nightwear such as shorts, pyjamas, t-shirt, or tracksuit bottoms. Nighties are not suitable. 

Are there any side-effects?

You will not feel anything during or after the recording. The machine records the normal natural activity seen during your sleep. After the equipment is removed, great care will be taken to remove as much of the glue as possible from your hair. Applying a hair conditioner and combing through your hair before having a shower or bath will help soften any glue left.

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on 0117 414 1048 or 0117 414 1052 and a member of staff will be happy to help.

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003750

Please read this information carefully before coming in for your actigraphy leading into an overnight polysomnography.

What is an actigraphy?

Actigraphy is a non-invasive way to find out your sleep patterns by monitoring your rest and activity cycles over 1 or two weeks.

Why have an actigraphy?

If you are having problems with your sleep such as irregular sleep and wake times, or excessive sleepiness, you may be referred for an actigraphy test.

What happens during an actigraphy?

Actigraphy monitors movement over days or weeks in real life situations. It involves wearing a device like a watch which has an accelerometer that detects movements.

You will wear the watch on your wrist at all times for around 2 weeks and complete a diary sheet of your daily activities and sleep times. You must only remove the watch when you shower, bathe, or wash and then log this on the diary sheet. It is important that you remember to re-attach the watch after this.

You will press a button on the watch when you go to bed and when you wake up. This will be fully explained to you by the clinical neurophysiologist at your initial appointment. During this appointment, you will be given some diary sheets to write down your daily activities whilst wearing the watch.

After you have completed your period of actigraphy you must return the watch in person at the time specified in your letter. These watches are in high demand for use by other patients and failure to return at the specified time may result in the cancellation of other patient’s appointments.

Preparing for the test

• You can eat and drink as normal before the test.
• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You will be asked if you understand this information and whether you consent to the test before we start. You are welcome to ask the neurophysiologist doing the test to give you any further information or to explain more about the procedures.
• Your appointment should take around 10-15 minutes.

What is a polysomnography?

Polysomnography (also known as sleep studies) is a test used to diagnose sleep disorders. Electrodes and sensors are placed on the body and head to record different information that allows your sleep to be studied in detail for 1 or 2 nights. A video recording is taken during the study to help diagnose your sleep problem.

Why do a polysomnography?

The main reason is to try to classify (work out exactly) the problem you are having with your sleep so that the referring doctors can treat it more effectively.

What happens during the test?

Small discs (electrodes) are applied to your scalp, around your eyes, and under your chin. These will be attached with special glue, so they do not fall off in your sleep.

2 belts will be placed around your chest and abdomen (tummy) that measure your breathing, with additional boxes attached where the wires are connected. A nasal cannula will rest in your nose to also measure breathing.

2 sticky pads will be placed: 1 on your shoulder and 1 on your hip to detect your heart rate. A pulse oximeter will be placed on your finger to detect blood oxygen saturation. A movement sensor is placed on your arm and 1 on each of your legs to detect any movements in your sleep.

The equipment will stay in place until the end of the test, and it is removed by a neurophysiologist.

The night-time recording is started as close to your normal sleep time as possible. Wake time is usually before breakfast at around 08:30.

It may be necessary to do a Multiple Sleep Latency Test (MSLT). This involves settling down to sleep at specific sections of the day. These periods are about 20-40 minutes and are about 2 hours apart. You will be woken up at the appropriate time by your neurophysiologist.

Preparation for the test 

Follow these instructions carefully for the MSLT

• Do not consume any alcohol, coffee, or stimulating drugs (medication) the night before or morning of the test.
• Stop smoking at least 30 minutes before each test.
• Do not doze off in-between the test sessions.

General preparation for polysomnography

• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You must arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• You will be set up in the clothes you sleep in, and won’t be able to change during the test. Please make sure you bring suitable nightwear such as shorts, pyjamas, t-shirt, or tracksuit bottoms. Nighties are not suitable. 

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Are there any side-effects?

You will not feel anything during or after the recording. The machine records the normal natural activity seen during your sleep. After the equipment is removed, great care will be taken to remove as much of the glue as possible from your hair. Applying a hair conditioner and combing through your hair before having a shower or bath will help soften any glue left.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003749

Please read this information carefully before coming in for your Visually Evoked Potential (VEP).

What is a VEP?

VEP is a test that assesses the functioning of the visual system, from the eye to the brain along the optic nerve. A VEP is a non-invasive, painless procedure, that records the electrical activity of the brain in response to an alternating checkerboard screen.

Why do a VEP?

If you are experiencing changes to your vision in 1 or both eyes, a VEP may be requested to determine whether there is a problem with how the visual pathways are functioning.

What happens during a VEP?

Your VEP will take around 60-90 minutes. First your head will be measured and several small electrodes will be attached with sticky paste to your head. 2 other discs will be placed to the side of your eyes and 2 further sticky pad electrodes will also be attached below the lower eyelid of each eye.

You will be asked to sit comfortably in a chair and look at a black and white checkerboard screen which will be moving from side to side.

Full-field VEP

At first you will have both eyes open and look at the alternating screen whilst focusing on a red dot. As the test continues 1 eye and then the other will be covered with an eye patch. You will be asked to watch the screen for several minutes so that plenty of responses can be collected and averaged, which will give us a good understanding about how the optic nerve pathway is working. The brain will respond to the moving checkerboard stimulus and these waveforms will be recorded.

Half-field VEP

This is an extension of the first test. Again your eyes will be covered 1 at a time by an eye patch but at the same time half of the checkerboard screen will also be covered.

Flash VEP

Sometimes you may be asked to complete a third part to the test. A strobe lamp will be placed a short distance away and you will be asked to watch this lamp as it flashes. Once the recording has finished all electrodes will be removed and your head wiped with warm water.

Preparing for the test

• You should arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• Continue taking all regular medication and eat as normal before the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment you are welcome to ask the physiologist doing the test to give you further information or to explain more about the procedure.

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003747

Please read this information carefully before coming in for your Somatosensory Evoked Potential (SEP). 

What is an SEP?

SEP stands for somatosensory evoked potential. It is a test that assesses the function of the sensory nerve pathways from the arms and legs to the brain, rather than taking images as you would see following a scan. It is a non-invasive procedure, that records the electrical activity of the brain in response to a series of small electrical impulses on your wrists and ankles.

Why do an SEP?

If you are experiencing numbness, weakness, or other problems in your arms and legs you may be referred for a SEP to see if there are any problems affecting your sensory nerve pathways to the brain.

What happens during the test? 

The SEP is usually split into 2 tests; an upper limb SEP where your wrist will be stimulated, and a lower limb SEP which involves ankle stimulation.

Each test will take around 45-60 minute. First your head will be measured, then a few small metal discs will be attached to your head, neck, collar bone, stomach, lower back, and behind your knees using a sticky paste, tape and possibly some glue.

Once everything is attached you will be asked to relax comfortably on a couch. Felt, stimulating pads are then attached either to the wrists or ankles. A small electrical impulse will then be applied to each wrist which will cause your thumb to twitch, this will then be repeated on each of your ankles causing your toes to twitch.

The series of impulses will continue for several minutes until all appropriate responses have been collected and recorded on the machine.

After the procedure the metal discs will be removed, and your head will be cleaned with warm water. If glue has been used, then some acetone (nail varnish remover equivalent) will be used to remove the discs.

Preparing for the test

• Wear loose fitting clothing to give easy access to your neck, back, arms, and legs when applying the metal discs.
• You should arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• Continue taking all regular medication and eat as normal before the test.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment you are welcome to ask the physiologist doing the test to give you further information or to explain more about the procedure.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003746

Please read this information carefully before coming in for your overnight polysomnography.

What is a polysomnography?

Polysomnography (also known as sleep studies) is a test used to diagnose sleep disorders. Electrodes and sensors are placed on the body and head to record different information that allow your sleep to be studied in detail for 1 or 2 nights. A video recording is taken during the study to help diagnose your sleep problem.

Why do a polysomnography?

The main reason is to try to classify (work out exactly) the problem you are having with your sleep so that the referring doctors can treat it more effectively.

What happens during the test?

Small discs (electrodes) are applied to your scalp, around your eyes, and under your chin. These will be attached with special glue, so they do not fall off in your sleep.

2 belts will be placed around your chest and abdomen that measure your breathing, with additional boxes attached where the wires are connected. A nasal cannula will rest in your nose to also measure breathing. 2 sticky pads will be placed: 1 on your shoulder and 1 on your hip to detect your heart rate. A pulse oximeter will be placed on your finger to detect blood oxygen saturation. A movement sensor is placed on your arm and 1 on each of your legs to detect any movements in your sleep.

The equipment will stay in place until the end of the test, and it is removed by a neurophysiologist.

The night-time recording is started as close to your normal sleep time as possible. Wake time is usually before breakfast at around 08:30.

Are there any side-effects?

You will not feel anything during or after the recording. The machine records the normal natural activity seen during your sleep. After the equipment is removed, great care will be taken to remove as much of the glue as possible from your hair. Applying a hair conditioner and combing through your hair before having a shower or bath will help soften any glue left.

Preparing for the test

• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You must arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• You will be set up in the clothes you sleep in, and won’t be able to change during the test. Please make sure you bring suitable nightwear such as shorts, pyjamas, t-shirt, or tracksuit bottoms. Nighties are not suitable.
• You will not be able to shower or bath during the monitoring period while the equipment is attached. This will be 1 or 2 nights and the equipment will stay in place for the whole time (including during the day). 

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on 0117 414 1048 or 0117 414 1052 and a member of staff will be happy to help.

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003745

Please read this information carefully before coming in for your actigraphy leading into an overnight polysomnography.

What is an actigraphy?

Actigraphy is a non-invasive way to find out your sleep patterns by monitoring your rest and activity cycles over 1 or 2 weeks.

Why have an actigraphy?

If you are having problems with your sleep such as irregular sleep and wake times, or excessive sleepiness, you may be referred for an actigraphy test.

What happens during an actigraphy?

Actigraphy monitors movement over days or weeks in real life situations. It involves wearing a device like a watch which has an accelerometer that detects movements.

You will wear the watch on your wrist at all times for around 2 weeks and complete a diary sheet of your daily activities and sleep times. You must only remove the watch when you shower, bathe, or wash and then log this on the diary sheet. It is important that you remember to re-attach the watch after this.

You will press a button on the watch when you go to bed and when you wake up. This will be fully explained to you by the clinical neurophysiologist at your initial appointment. During this appointment, you will be given some diary sheets to write down your daily activities whilst wearing the watch.

After you have completed your period of actigraphy you must return the watch in person at the time specified in your letter. These watches are in high demand for use by other patients and failure to return at the specified time may result in the cancellation of other patient’s appointments.

Preparing for the test

• You can eat and drink as normal before the test.
• Please follow the guidance provided by your consultant neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You will be asked if you understand this information and whether you consent to the test before we start. You are welcome to ask the neurophysiologist doing the test to give you any further information or to explain more about the procedures.
• Your appointment should take approximately 10-15 minutes.

What is a polysomnography?

Polysomnography (also known as sleep studies) is a test used to diagnose sleep disorders. Electrodes and sensors are placed on the body and head to record different information that allow your sleep to be studied in detail for 1 or 2 nights. A video recording is taken during the study to help diagnose your sleep problem.

Why do a polysomnography?

The main reason is to try to classify (work out exactly) the problem you are having with your sleep so that the referring doctors can treat it more effectively.

What happens during the test?

Small discs (electrodes) are applied to your scalp, around your eyes, and under your chin. These will be attached with special glue, so they do not fall off in your sleep.

2 belts will be placed around your chest and abdomen (tummy) that measure your breathing, with additional boxes attached where the wires are connected. A nasal cannula will rest in your nose to also measure breathing.

2 sticky pads will be placed: 1 on your shoulder and 1 on your hip to detect your heart rate. A pulse oximeter will be placed on your finger to detect blood oxygen saturation. A movement sensor is placed on your arm and 1 on each of your legs to detect any movements in your sleep.

The equipment will stay in place until the end of the test, and it is removed by a neurophysiologist.

The night-time recording is started as close to your normal sleep time as possible. Wake time is usually before breakfast at around 08:30.

Are there any side-effects?

You will not feel anything during or after the recording. The machine records the normal natural activity seen during your sleep. After the equipment is removed, great care will be taken to remove as much of the glue as possible from your hair. Applying a hair conditioner and combing through your hair before having a shower or bath will help soften any glue left.

Preparing for the test

• Please follow the guidance provided by your Consultant Neuropsychiatrist about reducing or stopping medications before coming for the test. This information should be in the clinic letter following your appointment. Please call 0117 414 1048 or 0117 414 0452 if you have any concerns or questions.
• You must arrive with clean, dry hair with no grease, gel, wax, or other hair products.
• You will be set up in the clothes you sleep in, and won’t be able to change during the test. Please make sure you bring suitable nightwear such as shorts, pyjamas, t-shirt, or tracksuit bottoms. Nighties are not suitable.
• You will not be able to shower or bath during the monitoring period while the equipment is attached. This will be 1 or two nights and the equipment will stay in place for the whole time (including during the day). 

How long until I get my results?

The results will be sent to your GP/consultant. You will not receive any results during the test. Your consultant may send you a letter with the results or see you again for a follow-up appointment. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on 0117 414 1048 or 0117 414 1052 and a member of staff will be happy to help.

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003744

Please read this information carefully before coming in for your Nerve Conduction Study (NCS) and/or Electromyography (EMG).

What is an NCS?

NCS stands for nerve conduction study. It is a test that assesses the function of the sensory and motor nerve pathways, allowing us to see how the nerves are working. It is a non-invasive procedure, that records the electrical activity from the nerves in response to a series of small electrical impulses.

Why do an NCS?

If you are experiencing numbness, weakness, or other changes in sensation to your hands or feet you may be referred for a NCS to see if there is evidence of a trapped nerve.

What happens during an NCS?

At the start of the test, contact sites on your hands and feet will be wiped with alcohol gel to ensure a good contact with the recording discs.

The NCS is split into 2 tests.

First the sensory nerve pathways will be tested. Some stimulating rings will be applied to the fingers, or a recording bar will be used on your feet. Sticky pads to record the responses will also be applied to your skin.

Once everything is attached you will feel small electrical impulses from the rings on your fingers. The series of impulses will continue for several seconds, and the responses will be recorded on the machine. The rings will then be removed.

During the second part of the test the motor pathways will be tested. The sticky recording pads will be moved to different areas of the skin. A stimulating bar will then be applied, and you will feel the small electrical impulses once again and this time cause some twitching of your fingers and arms (if recording from your upper limbs), and legs and toes (if recording from your lower limbs).

The series of impulses will continue for several seconds, and the responses will be recorded on the machine. Once the test is over all the sticky pads will be removed and your skin wiped and cleaned.

What is an EMG?

EMG stands for electromyography. It is a test that assesses the function of individual muscles, allowing us to see how they, and the motor nerve pathways which control them, are working.

Why do an EMG?

If you are experiencing numbness, tingling, cramping, or unexplained muscle weakness you may be referred for an EMG to see if there is evidence of a muscle disorder or nerve damage affecting the muscles.

What happens during an EMG?

An EMG will be done after the nerve conduction study. A fine needle is inserted into the muscle being examined and then the response will record while the muscle is resting, during slight activity and when fully active. To do this, you will be asked to slightly flex the muscle which will produce crackling sounds on our machine, the clinician will then ask you to fully flex the muscle to which will cause louder crackling sounds. 

This may be repeated on several different muscles depending on the reason you are having the test.

The test can vary from 30 minutes to an hour, although occasionally it may take longer. Because of this we cannot guarantee that you will be seen exactly at the time of your given appointment. We do try to keep to the appointment system, so please attend in good time.

Preparing for the test 

• Wear loose fitting clothing with easy access to your upper arms and legs when stimulating the nerves.
• Do not apply moisturising products to your hands and feet before the test as these can affect our ability to record responses.
• Continue taking all regular medication and eat as normal before the test.
• Please inform the department before attending if you are have from an infectious condition, a bleeding disorder, take warfarin (or other anti-coagulant medications), or have a cardiac pacemaker fitted.
• You will be asked if you understand this information and whether you consent to the test before we start. At your appointment you are welcome to ask the neurophysiologist doing the test to give you further information or to explain more about the procedures.

When will I get my results?

You will not get your results straight after the test or see a doctor on the day as the NCS and EMG need to be fully analysed. 

A full report will be sent to the GP or consultant who referred you within 2 weeks, they will then contact you to discuss the results. Please note, results are not sent directly to you.

Contact details

This information is intended as a guideline only. If you have any further questions about your test (excluding about results) please contact the department on the numbers below and a member of staff will be happy to help.

0117 414 1048 
0117 414 1050 

Your responsibility as a patient

Outpatient services at North Bristol NHS Trust are in great demand. Even so, every week an average of 600 patients fail to attend, which wastes appointments. Please tell us with as much notice as possible if you no longer need your appointment and we can allocate this to another patient. 

What if I am unwell or need to change my appointment?

If you have an infectious condition, such as COVID-19, measles, mumps, chickenpox, flu, stomach upset, have head lice, or are unable to attend your appointment for any other reason, please let us know with as much notice as possible so that your appointment can be rescheduled and offered to someone else.

If you want to change the appointment for a second time, we cannot offer you another date unless there are exceptional circumstances.

What if I don’t attend?

We will assume that you no longer require your appointment, and we will not offer you another one. We will write to the consultant/doctor who referred you and inform them that you did not attend.

© North Bristol NHS Trust. This edition published December 2024. Review due December 2027. NBT003743