This is the most common and widely recognised generalised seizure. A tonic-clonic seizure affects the entire brain. There are two phases to this type of seizure: the ‘tonic’ phase followed by the ‘clonic’ phase.

The tonic phase

Your body goes stiff because all your muscles contract. You may cry out because the muscles around your lungs contract, forcing out air. Your breathing patterns change with the result that there is less oxygen than normal in your lungs. Because of this, the blood circulating in your body is less red than usual, causing your skin (particularly around the mouth and under the finger nails) to appear blue in colour. This is called ‘cyanosis’.

The clonic phase

After the tonic phase has passed, the clonic phase of the seizure begins. Your limbs jerk because now your muscles tighten and relax in turn. It is not possible to stop the seizure and nobody should attempt to control your movements, as this could cause injury to your limbs. During the tonic phase you may bite your tongue and the inside of your cheeks.

Some people may occasionally be incontinent.

After a further minute or so, your muscles relax and your body goes limp. Slowly you will regain consciousness, but may well be groggy or confused. You will gradually return to normal but may not be able to remember anything for a while. Very often, you remain sleepy and may have a headache and aching limbs. Recovery times differ from person to person. Some people will quickly want to get back to what they were doing. Some people will need a short sleep and others will need plenty of rest. It is best to sleep for as long as you need.

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