Skip to Content

Seizures

Medically reviewed on March 3, 2018.

Overview

A seizure is a sudden, uncontrolled electrical disturbance in the brain. It can cause changes in your behavior, movements or feelings, and in levels of consciousness. If you have two or more seizures or a tendency to have recurrent seizures, you have epilepsy.

There are many types of seizures, which range in severity. Seizure types vary by where and how they begin in the brain. Most seizures last from 30 seconds to two minutes. A seizure that lasts longer than five minutes is a medical emergency.

Seizures are more common than you might think. Seizures can happen after a stroke, a closed head injury, an infection such as meningitis or another illness. Many times, though, the cause of a seizure is unknown.

Most seizure disorders can be controlled with medication, but management of seizures can still have a significant impact on your daily life. The good news is you can work with your health care professional to balance seizure control and medication side effects.

Symptoms

With a seizure, signs and symptoms can range from mild to severe and vary depending on the type of seizure. Seizure signs and symptoms may include:

  • Temporary confusion
  • A staring spell
  • Uncontrollable jerking movements of the arms and legs
  • Loss of consciousness or awareness
  • Cognitive or emotional symptoms, such as fear, anxiety or deja vu

Doctors generally classify seizures as either focal or generalized, based on how and where abnormal brain activity begins. Seizures may also be classified as unknown onset, if how the seizure began isn't known.

Focal seizures

Focal seizures result from abnormal electrical activity in one area of your brain. Focal seizures can occur with or without loss of consciousness:

  • Focal seizures with impaired awareness. These seizures involve a change or loss of consciousness or awareness. You may stare into space and not respond normally to your environment or perform repetitive movements, such as hand rubbing, chewing, swallowing or walking in circles.
  • Focal seizures without loss of consciousness. These seizures may alter emotions or change the way things look, smell, feel, taste or sound, but you don't lose consciousness. These seizures may also result in the involuntary jerking of a body part, such as an arm or leg, and spontaneous sensory symptoms such as tingling, dizziness and flashing lights.

Symptoms of focal seizures may be confused with other neurological disorders, such as migraine, narcolepsy or mental illness.

Generalized seizures

Seizures that appear to involve all areas of the brain are called generalized seizures. Different types of generalized seizures include:

  • Absence seizures. Absence seizures, previously known as petit mal seizures, often occur in children and are characterized by staring into space or by subtle body movements, such as eye blinking or lip smacking. These seizures may occur in clusters and cause a brief loss of awareness.
  • Tonic seizures. Tonic seizures cause stiffening of your muscles. These seizures usually affect muscles in your back, arms and legs and may cause you to fall to the ground.
  • Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control, which may cause you to suddenly collapse or fall down.
  • Clonic seizures. Clonic seizures are associated with repeated or rhythmic, jerking muscle movements. These seizures usually affect the neck, face and arms.
  • Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of your arms and legs.
  • Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the most dramatic type of epileptic seizure and can cause an abrupt loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting your tongue.

When to see a doctor

Seek immediate medical help if any of the following occurs:

  • The seizure lasts more than five minutes.
  • Breathing or consciousness doesn't return after the seizure stops.
  • A second seizure follows immediately.
  • You have a high fever.
  • You're experiencing heat exhaustion.
  • You're pregnant.
  • You have diabetes.
  • You've injured yourself during the seizure.

If you experience a seizure for the first time, seek medical advice.

Causes

Nerve cells (neurons) in the brain create, send and receive electrical impulses, which allow the brain's nerve cells to communicate. Anything that disrupts these communication pathways can lead to a seizure.

The most common cause of seizures is epilepsy. But not every person who has a seizure has epilepsy. Sometimes seizures happen because of:

  • High fever, which can be associated with an infection such as meningitis
  • Lack of sleep
  • Low blood sodium (hyponatremia), which can happen with diuretic therapy
  • Medications, such as certain pain relievers, antidepressants or smoking cessation therapies, that lower the seizure threshold
  • Head trauma that causes an area of bleeding in the brain
  • Stroke
  • Brain tumor
  • Illegal or recreational drugs, such as amphetamines or cocaine
  • Alcohol abuse, during times of withdrawal or extreme intoxication

Complications

Having a seizure at certain times can lead to circumstances that are dangerous for you or others. You might be at risk of:

  • Falling. If you fall during a seizure, you can injure your head or break a bone.
  • Drowning. If you have a seizure while swimming or bathing, you're at risk of accidental drowning.
  • Car accidents. A seizure that causes either loss of awareness or control can be dangerous if you're driving a car or operating other equipment.
  • Pregnancy complications. Seizures during pregnancy pose dangers to both mother and baby, and certain anti-epileptic medications increase the risk of birth defects. If you have epilepsy and plan to become pregnant, work with your doctor so that he or she can adjust your medications and monitor your pregnancy, as needed.
  • Emotional health issues. People with seizures are more likely to have psychological problems, such as depression and anxiety. Problems may be a result of difficulties dealing with the condition itself as well as medication side effects.

Diagnosis

After a seizure, your doctor will thoroughly review your symptoms and medical history. Your doctor may order several tests to determine the cause of your seizure and evaluate how likely it is that you'll have another one.

Tests may include:

  • A neurological exam. Your doctor may test your behavior, motor abilities and mental function to determine if you have a problem with your brain and nervous system.
  • Blood tests. Your doctor may take a blood sample to check for signs of infections, genetic conditions, blood sugar levels or electrolyte imbalances.
  • Lumbar puncture. If your doctor suspects an infection as the cause of a seizure, you may need to have a sample of cerebrospinal fluid removed for testing.
  • An electroencephalogram (EEG). In this test, doctors attach electrodes to your scalp with a paste-like substance. The electrodes record the electrical activity of your brain, which shows up as wavy lines on an EEG recording. The EEG may reveal a pattern that tells doctors whether a seizure is likely to occur again. EEG testing may also help your doctor exclude other conditions that mimic epilepsy as a reason for your seizure. Depending on the details of your seizures, this test may be done as an outpatient in the clinic, overnight at home with an ambulatory device or over a few nights in the hospital.
  • Computerized tomography (CT). A CT scan uses X-rays to obtain cross-sectional images of your brain. CT scans can reveal abnormalities in your brain that might cause a seizure, such as tumors, bleeding and cysts.
  • Magnetic resonance imaging (MRI). An MRI scan uses powerful magnets and radio waves to create a detailed view of your brain. Your doctor may be able to detect lesions or abnormalities in your brain that could lead to seizures.
  • Positron emission tomography (PET). A PET scan uses a small amount of low-dose radioactive material that's injected into a vein to help visualize active areas of the brain and detect abnormalities.
  • Single-photon emission computerized tomography (SPECT). A SPECT test uses a small amount of low-dose radioactive material that's injected into a vein to create a detailed, 3-D map of the blood flow activity in your brain that happens during a seizure. Doctors also may conduct a form of a SPECT test called subtraction ictal SPECT coregistered to MRI (SISCOM), which may provide even more-detailed results. This test is usually done in a hospital with overnight EEG recording.
EEG brain activity

An EEG records the electrical activity of your brain via electrodes affixed to your scalp. EEG results show changes in brain activity that may be useful in diagnosing brain conditions, especially epilepsy and other seizure disorders.

High-density EEG

During a high-density EEG test, electrodes are placed on your scalp closely spaced together. Like conventional EEG, high-density EEG records brain activity. A high-density EEG test can help your doctor locate the area in your brain where seizures occur.

CT scan

A CT scan can be used to visualize nearly all parts of the body and is used to diagnose disease or injury as well as to plan medical, surgical or radiation treatment.

Pinpointing seizure location

This example shows SPECT scans taken during and between seizures. The differences represent areas where blood flow increased during the seizure. Once identified, that location is fitted onto an MRI image of the brain.

Treatment

Not everyone who has one seizure will have another one, and because a seizure can be an isolated incident, your doctor may not decide to start treatment until you've had more than one.

The optimal goal in seizure treatment is to find the best possible therapy to stop seizures, with the fewest side effects.

Medication

Treatment for seizures often involves the use of anti-seizure medications. Several options exist for anti-seizure medications. The goal is to find the medicine that works best for you and that causes the fewest side effects. In some cases, your doctor might recommend more than one medication.

Finding the right medication and dosage can be complex. Your doctor will consider your condition, your frequency of seizures, your age and other factors when choosing which medication to prescribe. Your doctor will also review any other medications you may be taking, to ensure the anti-epileptic medications won't interact with them.

Surgery and other therapies

If anti-seizure medications aren't effective, other treatments may be an option:

  • Surgery. The goal of surgery is to stop seizures from happening. Surgeons locate and remove the area of your brain where seizures begin. Surgery works best for people who have seizures that always originate in the same place in their brains.
  • Vagus nerve stimulation. A device implanted underneath the skin of your chest stimulates the vagus nerve in your neck, sending signals to your brain that inhibit seizures. With vagus nerve stimulation, you may still need to take medication, but you may be able to lower the dose.
  • Responsive neurostimulation. During responsive neurostimulation, a device implanted on the surface of your brain or within brain tissue can detect seizure activity and deliver an electrical stimulation to the detected area to stop the seizure.
  • Deep brain stimulation. Doctors implant electrodes within certain areas of your brain to produce electrical impulses that regulate abnormal brain activity. The electrodes attach to a pacemaker-like device placed under the skin of your chest, which controls the amount of stimulation produced.
  • Dietary therapy. Following a diet that's high in fat and low in carbohydrates, known as a ketogenic diet, can improve seizure control. Variations on a high-fat, low-carbohydrate diet, such as the low glycemic index and modified Atkins diets, though less effective, aren't as restrictive as the ketogenic diet and may provide benefit.

Pregnancy and seizures

Women who've had previous seizures typically are able to have healthy pregnancies. Birth defects related to certain medications can sometimes occur.

In particular, valproic acid — one possible medication for generalized seizures — has been associated with cognitive deficits and neural tube defects, such as spina bifida. The American Academy of Neurology recommends that women avoid using valproic acid during pregnancy because of risks to the baby. Discuss these risks with your doctor. Because of the risk of birth defects and because pregnancy can alter medication levels, preconception planning is particularly important for women who've had seizures.

In some cases, it may be appropriate to change the dose of seizure medication before or during pregnancy. Medications may be switched in rare cases.

Contraception and anti-seizure medications

Some anti-seizure medications can alter the effectiveness of birth control (oral contraceptive) medication. If contraception is a high priority, check with your doctor to evaluate whether your medication interacts with your oral contraceptive, and if other forms of contraception need to be considered.

Vagus nerve stimulation

In vagus nerve stimulation, an implanted pulse generator and lead wire stimulate the vagus nerve, which leads to stabilization of abnormal electrical activity in the brain.

Deep brain stimulation

Deep brain stimulation involves implanting an electrode deep within your brain. The amount of stimulation delivered by the electrode is controlled by a pacemaker-like device placed under the skin in your chest. A wire that travels under your skin connects the device to the electrode.

Lifestyle and home remedies

Here are some steps you can take to help with seizure control:

  • Take medication correctly. Don't adjust the dosage before talking to your doctor. If you feel your medication should be changed, discuss it with your doctor.
  • Get enough sleep. Lack of sleep can trigger seizures. Be sure to get adequate rest every night.
  • Wear a medical alert bracelet. This will help emergency personnel know how to treat you correctly if you have another seizure.
  • Be active. Exercising and being active may help keep you physically healthy and reduce depression. Make sure to drink enough water and rest if you get tired during exercise.
  • Make healthy life choices. Managing stress, limiting alcoholic beverages and avoiding cigarettes all factor in to a healthy lifestyle.

Personal safety

Seizures don't usually result in serious injury, but if you have recurrent seizures, injury is a possibility. These steps can help you avoid injury during a seizure:

  • Take care near water. Don't swim alone or relax in a boat without someone nearby.
  • Wear a helmet for protection during activities such as bike riding or sports participation.
  • Take showers instead of baths, unless someone is near you.
  • Modify your furnishings. Pad sharp corners, buy furniture with rounded edges and choose chairs that have arms to keep you from falling off the chair. Consider carpet with thick padding to protect you if you do fall.
  • Display seizure first-aid tips in a place where people can easily see them. Include any important phone numbers there, too.

Seizure first aid

It's helpful to know what to do if you witness someone having a seizure. If you're at risk of having seizures in the future, pass this information along to family, friends and co-workers so that they know what to do if you have a seizure.

To help someone during a seizure, take these steps:

  • Carefully roll the person onto one side
  • Place something soft under his or her head
  • Loosen tight neckwear
  • Avoid putting your fingers or other objects in the person's mouth
  • Don't try to restrain someone having a seizure
  • Clear away dangerous objects, if the person is moving
  • Stay with the person until medical personnel arrive
  • Observe the person closely so that you can provide details on what happened
  • Time the seizure
  • Stay calm

Coping and support

If you're living with a seizure disorder, you may feel anxious or stressed about what your future holds. Stress can affect your mental health, so it's important to talk with your health care professional about your feelings and seek ways you can find help.

At home

Your family can provide much-needed support. Tell them what you know about your seizure disorder. Let them know they can ask you questions, and be open to conversations about their worries. Help them understand your condition by sharing any educational materials or other resources that your health care professional has given you.

At work

Meet with your supervisor and talk about your seizure disorder and how it affects you. Discuss what you need from your supervisor or co-workers if a seizure happens while at work. Consider talking with your co-workers about seizure disorders — you can widen your support system and bring about acceptance and understanding.

You're not alone

Remember, you don't have to go it alone. Reach out to family and friends. Ask your health care professional about local support groups or join an online support community. Don't be afraid to ask for help. Having a strong support system is important to living with any medical condition.

Preparing for an appointment

In some cases, seizures need immediate medical attention, and there's not always time to prepare for an appointment.

In other cases, your first appointment to evaluate a seizure may be with your family doctor or a general practitioner. Or you may be referred to a specialist, such as a doctor trained in brain and nervous system conditions (neurologist) or a neurologist trained in epilepsy (epileptologist).

To prepare for your appointment, consider what you can do to get ready and understand what to expect from your doctor.

What you can do

  • Record information about the seizure. Include the time, location, symptoms you experienced and how long it lasted, if you know these details. Seek input from anyone who may have seen the seizure, such as a family member, friend or co-worker, so that you can record information you may not know.
  • Be aware of any pre-appointment restrictions. At the time you make the appointment, ask if there's anything you need to do in advance to be ready for any medical tests or exams.
  • Make a note of key personal information, including things like recent life changes, or major stresses.
  • Make a list of all medications, vitamins or supplements that you're taking, including dosages.
  • Take a family member or friend along, to help you remember all the information provided during an appointment. Also, because you may not be aware of everything that happens when you're having a seizure, your doctor may want to ask questions of someone who was a witness.
  • Write down questions to ask your doctor. Preparing a list of questions will help you make the most of your time with your doctor.

For seizures, some basic questions to ask your doctor include:

  • What do you think caused my seizure?
  • Do I need to have any tests done?
  • What treatment approach do you recommend?
  • What are the alternatives to the primary approach that you're suggesting?
  • How likely is it that I might have another seizure?
  • How can I make sure that I don't hurt myself if I have another seizure?
  • I have these other health conditions. How can I best manage them together?
  • Are there any restrictions that I need to follow?
  • Should I see a specialist? What will that cost, and will my insurance cover it?
  • Is there a generic alternative to the medicine you're prescribing?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor

Your doctor is likely to ask you a number of questions:

  • Can you describe your seizure episode?
  • Where were you and what happened right before it started?
  • Was anyone there to witness what happened?
  • What do you remember feeling just before the seizure? What about right after the seizure?
  • What symptoms did you experience?
  • How long did the seizure last?
  • Have you ever had a seizure or other neurological problem in the past?
  • Do you have any family members who have been diagnosed with a seizure disorder or epilepsy?
  • Have you recently traveled outside the country?

© 1998-2018 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use

Learn more about Seizures

Associated drugs

Micromedex® Care Notes

Mayo Clinic Reference

Hide