A seizure is a condition where a person loses all control over voluntary muscle control. Seizures always indicate a serious underlying condition and usually require medical attention unless they are the result of a previously diagnosed condition. They are generally classified into three types. Roughly in order of severity, they are:
Petit mal - The patient becomes "frozen" and cannot voluntarily move any part of the body. The patient may try to speak, but any words that are recognizable are not appropriate to the situation. There may be minor tremors or spasms, but for the most part the patient is still. The patient is usually aware of their surroundings and can recognize and understand those around them, but can take no action to respond to stimulus, although they may still have normal reflexes.
Absence - The person is also frozen, but may remain standing and cannot speak. When the seizure passes, the person will generally not realize that they have been without responses unless they have been moved in the meantime, in which case they become confused about how they got there.
Grand mal - The patient loses all control over voluntary movement and usually collapses if they were standing. They start having convulsions, and their limbs may thrash wildly. They may or may not be aware of their surroundings. They are totally incapable of responding to stimuli.
Complex partial - The patient appears to be conscious but in reality has no voluntary control over their actions and may be unresponsive to conversation (similar to sleepwalking, but the patient is fully awake). The patient may engage in routine tasks but will be unable to engage in complicated behaviors such as conversation or using a computer. The patient will generally have no recollection of the seizure and may pass in and out of such a state for several hours.
When a person suffers from a seizure, the best course of action is to make them as comfortable as possible and remove anything from the vicinity that might cause them injury. It is inappropriate to hold a seizure patient down as this might result in injury to either the patient or the person holding them. Similarly, it is inappropriate to try to reach into the mouth of a seizure patient to insure they don't choke - this usually results in serious injury to the person trying it. Once violent convulsions have passed, it is appropriate to administer oxygen, but usually no other treatment is required. A person who has suffered a seizure usually recovers quickly and requires reassurance once the episode has passed.