How epilepsy is diagnosed

Diagnosing epilepsy is not simple. Doctors gather lots of different information to assess the causes of seizures. If you have had two or more seizures that started in the brain you may be diagnosed with epilepsy.

Getting a diagnosis is not always easy as there is no single test that can diagnose epilepsy. If there is a possibility that you have epilepsy, NICE recommends that you are referred to a specialist, (a doctor who is trained in diagnosing and treating epilepsy) within two weeks.

Your diagnosis is based on finding out what happened to you before, during and after your seizures. For example, some types of faints can look like epileptic seizures, and often before fainting a person feels cold, clammy and their vision goes blurry. But epileptic seizures happen very suddenly and a person may have no warning that a seizure is about to happen. 

Recording information about your seizures

If you have a seizure you may not remember what has happened. It can be helpful to have a description of what happened from someone who saw your seizure, to pass on to your GP or specialist.

Here are some questions that may help you or someone who witnessed your seizure to record useful information about what happened.

Before the seizure

• Did anything trigger (set off) the seizure – for example, did you feel tired, hungry, or unwell?
• Did you have any warning that the seizure was going to happen?
• Did your mood change – for example, were you excited, anxious or quiet?
• Did you make any sound, such as crying out or mumbling?
• Did you notice any unusual sensations, such as an odd smell or taste, or a rising feeling in your stomach?
• Where were you and what were you doing before the seizure?

During the seizure

• Did you appear to be ‘blank’ or stare into space?
• Did you lose consciousness or become confused?
• Did you do anything unusual such as mumble, wander about or fiddle with your clothing?
• Did your colour change (become pale or flushed) and if so, where (face or lips)?
• Did your breathing change (for example, become noisy or look difficult)?
• Did any part of your body move, jerk or twitch?
• Did you fall down, or go stiff or floppy?
• Did you wet yourself?
• Did you bite your tongue or cheek?

After the seizure

• How did you feel after the seizure – did you feel tired, worn out or need to sleep?
• How long was it before you were able to carry on as normal?
• Did you notice anything else?

Looking at your medical history

Apart from the description of the seizure, there are other things that can help to explain why your seizures have happened. Your medical history and any other medical conditions will also be considered as part of your diagnosis. Sometimes the cause of someone’s epilepsy can be found. For example, following a head injury, a brain infection (such as meningitis) or a stroke. Some inherited conditions, (passed from parent to child) such as tuberous sclerosis, can cause epilepsy. However, for most people there are no clear reasons why they have epilepsy.

Information updated: October 2021