Seizures are caused by a sudden electrical overactivity in the nerve tissue of the brain.

Seizures can also be called fits, attacks, spells, convulsions, or epilepsy.

There are two main types of seizures: partial seizures and generalised seizures.

Partial seizures. These are often minor. They may cause symptoms such as momentary loss of speech or an abnormal sensation (like smelling burning or thinking you are watching what is happening rather than actually being there). They usually cause few if any problems.

Generalised seizures (tonic-clonic) are more noticeable.

Sometimes they begin with a brief change in sensation, known as an aura. This can be tingling in an arm or leg, seeing very bright lights, an alteration in smell or taste or a sudden feeling of anxiety. For some people, there is no aura and the seizure comes on without warning.

The first sign of the seizure may be as the person loses consciousness. Their muscles stiffen, and they fall to the ground. Sometimes the person may seem to cry out. This is caused by muscles in the chest contracting and forcing air out of the lungs.

After a few seconds the person's muscles begin to contract and relax repeatedly. this causes twitching and jerking movements. The person's breathing may be irregular. Sometimes a bluish tinge appears around their lips (cyanosis). Occasionally there may be temporary loss of bladder control and the person may wet themselves.

After a few minutes the jerking movements stop and the person becomes limp. They may stay unconscious for a few minutes. When they wake up they will not remember the seizure and may have a headache or feel dizzy or confused for a while. They may feel very tired and go onto have a normal but deep sleep.

During the seizure there is complete loss of consciousness and it's not possible to communicate with the person who is having the attack.

Unless they hurt themselves as they fall, people usually suffer no harm as a result of the fit and will be physically and mentally back to normal soon afterwards.

Any type of scarring to the brain can lead to seizures. As an operation on the brain will leave scar tissue, anyone who has surgery to the brain is at risk of developing fits. If this happens medication to control seizures (anti-epileptic tablets) can be prescribed.

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