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 watch. 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.

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

• Brief blackout followed by period of confusion
• Sudden falling
• Drooling or frothing at the mouth
• Grunting and snorting
• Breathing stops temporarily
• Uncontrollable muscle spasms with twitching and jerking limbs
• Loss of bladder or bowel control
• Eye movements
• Teeth clenching
• Unusual behavior like sudden anger, sudden laughter, or picking at one's clothing