What happens during a tonic seizure?
If a tonic seizure starts in both sides of the brain, all your muscles tighten and your body goes stiff. If you’re standing, you may fall to the floor. Your neck will extend, your eyes open wide and roll upwards. Your arms may raise upwards and your legs stretch or contract. You may cry out or stop breathing during the seizure.
If a tonic seizure starts in one side of the brain, your muscles tighten in just one area of the body.
Depending on the type of epilepsy the you have, tonic seizures might be more likely to happen when you are asleep.
How long do tonic seizures last?
Tonic seizures are short usually lasting less than 60 seconds. Some people tend to have clusters of tonic seizures, where they have several seizures in a short space of time.
What happens after a tonic seizure?
Once a tonic seizure has ended, your muscles relax. You might feel sleepy or confused afterwards.
If this is your first tonic seizure
If you think you have had a tonic seizure, make an appointment to see a doctor. They can decide if any tests or a referral to a specialist are needed. We have more information on our diagnosis page.
Tonic seizure first aid
This short video at the top of the page will show you how to help someone having a tonic seizure.
How to help
- Protect the person from injury and remove any harmful objects from nearby
- Time the seizure, to make sure it lasts less than 5 minutes
- Stay with them until they have fully recovered
- Be calm and reassuring
Other advice
It’s important that you don’t hold the person down or move them unless they are in danger. You shouldn’t try to bring them round and never give them anything to eat or drink until they are fully recovered. They might feel groggy for a few minutes, especially if they have had a cluster of seizures.
If a tonic seizure stops by itself and the person isn’t injured, they won’t usually need medical help.
Call for an ambulance if:
- A seizure lasts longer than 5 minutes
- One seizure follows another without them recovering in between
- They are badly injured during the seizure
Got more questions?
Our expert advisors can help you with any questions you might have about tonic seizures or anything else related to living with epilepsy.
This information is currently being reviewed and will be updated soon.