Convulsions are when a person's body shakes rapidly and uncontrollably. During convulsions, the person's muscles contract and relax repeatedly.

The term "convulsion" is often used interchangeably with "seizure," although there are many types of seizure, some of which have subtle or mild symptoms instead of convulsions. Seizures of all types are caused by disorganized and sudden electrical activity in the brain.

Convulsions can be unsettling to witness. Despite their appearance, most seizures are relatively harmless. They usually last from 30 seconds to 2 minutes. However, if a seizure is prolonged, or if multiple seizures happen and the person doesn't awaken in between, this is a medical emergency.

If a person has recurring seizures, and there are no underlying causes that can be identified, that person is said to have epilepsy. Epilepsy can usually be controlled well with medication.

It is not possible to stop a convulsion once it has started. All that can be done is to protect the person from injury and get medical help as needed.

Pay attention to which arms or legs are shaking, whether there is any change in consciousness, whether there is loss of urine or stool, and whether the eyes deviate in any direction.

• Epilepsy
• Alcohol use
• Barbiturates, intoxication or withdrawal
• Brain illness or injury
• Brain tumor (rare)
• Choking
• Drug abuse
• Electric shock
• Fever (particularly in young children)
• Head injury
• Heart disease
• Heat illness (see heat intolerance)
• Malignant hypertension (very high blood pressure)
• Meningitis
• Poisoning
• Stroke
• Toxemia of pregnancy
• Uremia related to kidney failure
• Venomous bites and stings (see snake bite)
• Withdrawal from benzodiazepines (such as Valium)
• Low blood sugar