Tonic-clonic seizures

A tonic-clonic seizure is what most people think of when they think of a seizure: losing consciousness, muscles stiffening, and seeing jerking movement. In the past they were called grand-mal seizures.

What happens

There are 2 phases: the tonic phase, followed by the clonic phase.

During the tonic phase:

• Loss of consciousness – they won’t be aware of what’s happening
• Muscles going stiff and falling to the floor, if standing
• Crying out – this is the sound of air being squeezed out of the lungs, not because they are in pain
• They might bite their tongue or the inside of their mouth

Then, during the clonic phase:

• Quick and rhythmic jerking of their limbs
• They may lose control of their bladder and/or bowels
• A blue tinge around the mouth, if their breathing is affected
• They may dribble, and you might see blood in it if they have bitted their tongue

How long does a tonic-clonic seizure last?

Most tonic-clonic seizures last between 1 and 3 minutes, but they can last longer for some people.

What happens afterwards

The time it takes to recover varies. Some people feel better after an hour or two. Others can take a few days before they feel back to normal.

After a tonic-clonic seizure the person might have a headache, feel sore, tired and unwell.  Sometimes people are confused, have unusual behaviour or their memory might be affected. Some people need to sleep to help them recover.

Sometimes people experience a temporary weakness or can’t move part of their body after a seizure. This is called Todd’s paresis or Todd’s paralysis. It can last from a few minutes to a few days before going away.

How to help

For how to help someone who is having a tonic-clonic seizure, go to the first aid for seizures information.

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