Seizures vs. strokes: key differences

  • July 12, 2023
  • 3
In this article
A doctor speaking to a patient about the differences between strokes and seizures

Strokes and seizures are two serious medical events which affect the brain. Although they are caused by very different things, some of the symptoms may look similar and could be confused with one another. 

Let's look at the differences between strokes and seizures, and some of the ways they may be linked to one another.

Seizure vs. stroke

What is a stroke?

A stroke is when part of your brain loses its blood supply. Most strokes are caused by a blocked artery - this is usually when a blood clot travels into the brain and prevents blood from reaching where it needs to go. Another cause of a stroke is a hemorrhage, which is when a blood vessel in the brain bursts.

A stroke is a major medical emergency, and can be life threatening. If someone is having a stroke, you must call 911 and seek medical attention immediately. When treated early (or if the stroke was mild), people can make a full recovery. For some people, though, a stroke can cause brain damage and lifelong disability.

The FAST acronym can help tell if you, or someone you are with, are having a stroke:

F - Face droops, usually on one side

A - Arm goes limp

S - Speech becomes slurred

T - Time to call 911

What is a seizure?

A seizure is an uncontrolled burst of electrical activity in your brain. Most of the time electrical signals are sent around the brain in an ordered manner, but during a seizure this activity gets disrupted.  

Seizures are not always medical emergencies. If someone has already been diagnosed with epilepsy, you do not always need to call an ambulance. But if a seizure lasts for more than five minutes then it is considered a medical emergency, and you should call 911.

Seizures can have many symptoms depending on where in the brain they begin. Often, a person may appear to ‘go blank’, and make repetitive movements with their hands, lips, or legs. Sometimes, a person having a seizure may shout out, fall to the ground, and jerk uncontrollably.

If someone is having a seizure, follow the STAY, SAFE, SIDE procedure:

  • STAY with the person, remain calm and check your watch to time the seizure (if it lasts five minutes or more, call 911)
  • Keep the person SAFE. Keep them away from sharp items, heat sources and water. If they are walking about, gently guide them away from danger, such as road traffic. Do not try to put anything in their mouth (it’s impossible to swallow your tongue).
  • If the person is on the ground, try to gently turn them on their SIDE if they are not awake or aware.

First aid: Simple seizure first aid guide

Seizures after a stroke

If you’ve had a stroke, you may go on to have a seizure in the days, weeks or months after the event. This does not necessarily mean you will develop epilepsy (which is when you have two or more unprovoked seizures), but you should seek medical help if this does happen.

Between 6% and 15% of people who have strokes do develop epilepsy. If you begin having seizures after a stroke, book an appointment with your physician as soon as possible.

Related: Brain trauma and seizures

Can a seizure cause a stroke?

In and of themselves, seizures are not a cause of strokes. As noted above, strokes (usually) happen because of blood clots, which prevent blood getting into the brain. A seizure won’t cause blood clots or hemorrhages.

It is important to be aware that there does seem to be a link between epilepsy and strokes. Studies have found that people with epilepsy are at a higher risk of having strokes. We don't know why this is yet.

Strokes and seizures

If you are concerned about strokes and seizures, then it’s always valuable to speak to your physician for personalized advice. They can help you understand your risks, and how to manage them.

Share article

Get the #1 epilepsy app now

Read next