Tonic-clonic seizures

« Back to Glossary Index

This type of seizure (also called a convulsion) is what most people think of when they hear the word “seizure.” An older term for this type of seizure is “grand mal.” As implied by the name, they combine the characteristics of tonic and clonic seizures. Tonic means stiffening, and clonic means rhythmical jerking.

The tonic phase comes first.
All the muscles stiffen.
Air being forced past the vocal cords causes a cry or groan.
The person loses consciousness and falls to the floor.
A person may bite their tongue or inside of their cheek. If this happens, saliva may look a bit bloody.
After the tonic phase comes the clonic phase.
The arms and usually the legs begin to jerk rapidly and rhythmically, bending and relaxing at the elbows, hips, and knees.
After a few minutes, the jerking slows and stops.
The person’s face may look dusky or a bit blue if they are having trouble breathing or the seizure lasts too long.
The person may lose control of their bladder or bowel as the body relaxes.
Consciousness, or a person’s awareness, returns slowly.
These seizures generally last 1 to 3 minutes. Afterwards, the person may be sleepy, confused, irritable, or depressed.
A tonic-clonic seizure that lasts longer than 5 minutes needs immediate medical help. Call 911 for emergency help.
A seizure that lasts more than 5 minutes, or three seizures in a row without the person coming to between them, is a dangerous condition. This is called status epilepticus; emergency treatment in a hospital is needed.

« Back to Glossary Index