Seizures: Signs, First Aid and Causes

What a seizure looks like

Seizures vary widely depending on where in the brain they start and how far they spread.

• Tonic-clonic (convulsive) seizure: the person may cry out, fall, go stiff, then jerk rhythmically. Breathing may be noisy, lips can turn blue, they may bite their tongue or wet themselves. Afterward they are confused, tired and may sleep.
• Absence seizure: a blank stare for 5 to 20 seconds, sometimes with fluttering eyelids, then they carry on as if nothing happened. Most common in children.
• Focal aware seizure: the person stays awake but has jerking of one limb, tingling, a sudden smell or taste, déjà vu, a rising feeling in the stomach or intense fear.
• Focal impaired awareness seizure: a vacant look with automatic movements such as lip smacking, chewing, fumbling with clothes or wandering, with no memory afterward.
• Myoclonic seizure: sudden brief jerks, often of the arms, typically soon after waking.
• Atonic seizure (drop attack): sudden loss of muscle tone and falling.

For the full classification of seizure types, diagnosis and long-term treatment, see the condition page on seizures.

Seizure first aid: what to do

For a convulsive seizure

1. Stay calm and time it.
2. Keep them safe: move hard or sharp objects away. Cushion the head with something soft.
3. Do not hold them down or try to stop the movements.
4. Do not put anything in their mouth. People cannot swallow their tongue.
5. Loosen tight clothing around the neck and remove glasses.
6. When jerking stops, roll them onto their side (recovery position) to keep the airway clear.
7. Stay with them until they are fully awake, and speak calmly. Do not give food or drink until fully alert.
8. Call 911 if any of the emergency signs above apply.

If the person has a rescue medicine plan, such as a nasal or buccal benzodiazepine, give it as directed.

For a non-convulsive seizure

Gently guide the person away from danger such as roads, stairs or water. Do not restrain them. Stay with them until they are fully aware.

What causes a seizure

Epilepsy

Epilepsy is the tendency to have repeated, unprovoked seizures. It affects about 1 in 100 people. Triggers for someone with epilepsy include missed medicines, lack of sleep, alcohol, illness, stress and, in some people, flashing lights.

Fever in young children

Febrile seizures affect 2 to 5 in 100 children between 6 months and 5 years during a fever, usually on the first day of an illness. Most last under 5 minutes and cause no lasting harm. See fever in children.

Provoked seizures (acute symptomatic)

These happen because of a temporary problem affecting the brain:

• Low blood sugar (hypoglycemia), especially in people taking insulin or sulfonylureas
• Alcohol withdrawal, typically 6 to 48 hours after the last drink. See alcohol withdrawal.
• Withdrawal from benzodiazepines or barbiturates
• Low sodium, calcium or magnesium, and kidney or liver failure
• Drugs: cocaine, amphetamines, and overdose of tramadol, bupropion or some antidepressants
• Sleep deprivation
• Eclampsia in pregnancy or soon after birth

Brain injury and disease

• Head injury, at the time or months to years later
• Stroke, the most common cause of new seizures in older adults
• Brain infections: meningitis, encephalitis and brain abscess
• Brain tumors
• Dementia
• Genetic and developmental conditions in children

Things that look like seizures

• Fainting (syncope): brief loss of consciousness, often with a few jerks, but quick recovery without prolonged confusion. Usually triggered by standing, heat, pain or fear.
• Psychogenic non-epileptic seizures: real, involuntary episodes caused by psychological stress rather than abnormal brain electrical activity.
• Migraine, panic attacks, sleep disorders and heart rhythm problems.

After a first seizure: what happens next

Doctors will want a detailed description, so if you witness a seizure, note what happened just before, how it started, how long it lasted and how the person recovered. A phone video is very helpful.

Tests usually include:

• blood tests for sugar, sodium, calcium, magnesium, kidney and liver function, and drug or alcohol levels
• an ECG to check heart rhythm
• brain imaging, usually MRI, sometimes urgent CT
• an EEG (brain wave test)
• lumbar puncture if infection is suspected

After a single unprovoked seizure, the chance of another is roughly 1 in 3 to 1 in 2 over the next few years. A neurologist will discuss whether to start treatment based on the EEG, MRI and other risk factors.

Safety after a seizure

• Driving: most US states and many countries require a seizure-free period before driving again, often 3 to 12 months. Check your local rules.
• Water: shower rather than bathe, and swim only with supervision.
• Heights and machinery: avoid until seizures are controlled.
• Sleep and alcohol: keep regular sleep and limit alcohol.

Frequently asked questions

What are the signs of a seizure?

Signs include sudden stiffening and jerking, falling, staring spells, unresponsiveness, lip smacking or fumbling movements, sudden confusion, and unusual sensations such as tingling, smells or déjà vu. After a convulsive seizure, the person is usually confused and sleepy.

What should you do when someone has a seizure?

Keep them safe from injury, cushion their head, do not restrain them or put anything in their mouth, time the seizure, and roll them onto their side when the jerking stops. Call 911 if it lasts more than 5 minutes, it is their first seizure or they do not wake up.

What can cause a seizure in someone without epilepsy?

Low blood sugar, alcohol or drug withdrawal, high fever in young children, low sodium, head injury, stroke, brain infections, some drugs and medicines, severe sleep deprivation and eclampsia in pregnancy can all cause a seizure in someone without epilepsy.

How long does a seizure last?

Most seizures last 30 seconds to 2 minutes. A seizure longer than 5 minutes, or repeated seizures without recovery between them, is a medical emergency called status epilepticus. Confusion and tiredness can last minutes to hours afterward.

Is a seizure dangerous?

Most brief seizures do not damage the brain, but injuries from falls, drowning and burns are real risks. Prolonged seizures can harm the brain and need emergency treatment. People with uncontrolled epilepsy have a small risk of sudden death, which good seizure control reduces.