Brain cells, also called neurons, send electric messages to each other, allowing the brain to control everything that goes on in the body. A seizure is a sudden surge of extra electrical activity in the brain that, unlike the other messages sent by neurons, confuse the body.
Seizures can alter awareness, physical movements, emotions, or actions, and generally last a few seconds to a few minutes. Seizures can take on many different forms and affect people very differently. After a seizure, a person might feel sick, weak, or confused.
The seizure itself is not a disease; it is considered a symptom of epilepsy. While all epileptic seizures are caused by electrical disturbances in the brain, there are many different kinds of seizures. Some people have just one type, while others may have a combination of seizure types. Behavior, risk of injury, and treatment depend upon the type of seizures.
Most seizures occur without warning, although some people have a funny feeling or a weird smell or taste right before a seizure. This is called an aura. Others find that certain things may trigger a seizure, like not getting enough sleep, stress, anxiety, and hormonal changes. A seizure can happen anywhere, at any time.
The kind of seizure a person has depends on whether the whole brain is affected (called a generalized seizure), or if just a part of the brain is affected (called focal seizures).
Focal seizures can look different from person to person because the way the seizure appears depends on what part or parts of the brain are affected. Focal seizures may or may not disrupt a person’s awareness.
The most commonly recognized type of seizure is a generalized tonic-clonic (formerly called a grand mal) seizure. When people think of this type of seizure, they usually think of someone falling down unconscious and shaking. Tonic-clonic seizures usually last for several minutes.
Another common type of generalized seizure, especially in young children, is an absence (formerly called a petit mal) seizure that is characterized by a blank stare, beginning and ending abruptly, and lasting only a few seconds. This type of seizure may also be accompanied by rapid eye blinking or chewing movements of the mouth. While this type of seizure involves loss of awareness, the person having an absence seizure will quickly return to full awareness.
These are examples of the most common types of seizures. Other seizure types include atonic, myoclonic, and psychogenic non-epileptic seizures. See Seizure Recognition and First Aid.