Medically Reviewed By William C. Lloyd III, MD, FACS

What are seizures?

Seizures are uncontrolled body spasms or convulsions due to abnormal patterns of electrical activity in the brain. Because the entire brain, or any part of the brain, can be affected, there are many types of seizures with many manifestations. Seizure causes include almost any type of damage to the brain, including injury and infection. Recurrent seizures are a sign of epilepsy.

Seizures generally stop on their own. Because someone having a seizure is unconscious, it is important to help the person avoid self-injury. Following a seizure, the person may be tired and require rest. Weakness, fatigue, and changes in mood and behavior are normal seizure symptoms that can appear afterwards.

When seizures occur, it is important to get a medical evaluation. For recurrent seizures or epilepsy, doctors may prescribe medications. In severe cases, surgery or electrical stimulation may be necessary. In many cases, treating the underlying cause of the seizures will help resolve them.

Seek immediate medical care (call 911) for any seizure, as prompt medical treatment may reduce the risk and severity of future seizures.

What are the types of seizures?

There are several different seizure types. Doctors classify them by where they start in the brain, a person’s level of awareness, and if muscles and movement are involved. There are two broad types of seizures based on the first criteria: generalized and focal.

Generalized seizures

Generalized seizures start in both sides of the brain and affect all areas. Common types of generalized seizures include:

  • Absence seizures are brief spells when someone stops moving and stares into space, looks blank, or may blink rapidly. This seizure lasts for several seconds and looks similar to someone who is daydreaming. The person may not remember the seizure. Another name for this seizure is a petit mal seizure.

  • Atonic seizures are a sudden loss of muscle tone. These short seizures cause the body to go limp, which results in the person falling to the ground. Injury is common with these seizures, which are also called drop attacks. They are common with syndromes such as Lennox-Gastaut. The person usually has impaired awareness during the seizure.

  • Myoclonic seizures are quick jerks or jolts in groups of muscles lasting only a second or two. The person remains alert and aware. This kind of seizure looks very similar to a tic.

  • Tonic seizures are a sudden increase in muscle tone, causing the body to go stiff or rigid. Falls are common with this seizure and the person is usually aware of the seizure.

  • Tonic-clonic seizures have two phases. The first tonic phase causes increased muscle tone. The following clonic phase causes rhythmic muscle jerking. During the seizure, the person loses consciousness and falls. These seizures can be quite long, lasting up to three minutes. Emergency medical treatment is necessary for seizures lasting five minutes or more or that recur rapidly. Another name for this seizure is grand mal. To most folks it is what they most commonly envision as a seizure.

Focal seizures

Focal seizures begin in one area of the brain. Because they only affect part of the brain, another name for them is partial seizures. There are three main types of focal seizures:

  • Simple focal seizures have four subtypes depending on the area of the brain that is causing symptoms. Motor seizures cause jerking in a body part, such as a foot or arm. Sensory seizures change the senses, such as having a strange taste in the mouth. Autonomic seizures affect bodily functions, such as loss of bladder function. Psychic seizures trigger emotions or memories, such as déjà vu or sudden fear. The person is conscious of these seizures, which are also known as auras or focal aware seizures.

  • Complex focal seizures affect a larger area of the brain. An aura often precedes this seizure, which causes a person to stare or have automatisms—repetitive movements with no purpose, such as lip smacking. This kind of seizure affects consciousness and is also called a focal unaware seizure.

  • Secondarily generalized seizures start as a focal seizure, but spread to all areas of the brain and become convulsive. They are very similar to generalized seizures.

What other symptoms might occur with seizures?

Seizures may accompany other symptoms, which vary depending on the underlying disease, disorder or condition. Symptoms that frequently affect the brain may also involve many other systems.

Perceptual symptoms that may occur along with seizures

Seizures may accompany other symptoms affecting your sensations and perceptions including:

  • Changes in hearing, taste or smell

  • Changes in mood, personality or behavior

  • Confusion or loss of consciousness for even a brief moment

  • Difficulty with memory

  • Hallucinations

  • Loss of vision or changes in vision

Other symptoms that may occur along with seizures

Seizures may accompany symptoms related to other body systems including:

Serious symptoms that might indicate a life-threatening condition

Seizures can be a symptom of a life-threatening condition that should be evaluated immediately in an emergency setting. Seek immediate medical care (call 911) for any seizure, as prompt medical treatment may reduce the risk and severity of future seizures.

What causes seizures?

Seizures can arise from any disorder, event or disease that damages the brain and stimulates unusual electrical activity. In some cases, seizures may result from medication side effects. Developmental factors may also lead to seizures. Finally, in some cases, seizures may not have a known cause.

Disease and disorder causes of seizures

Seizures can be caused by a variety of diseases and disorders including:

  • Acquired immunodeficiency syndrome (AIDS)

  • Dementia

  • Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)

  • Huntington’s disease (a genetic disorder causing nerve cells in the brain to waste away)

  • Meningitis (infection or inflammation of the sac around the brain and spinal cord)

  • Multiple sclerosis (disease that affects the brain and spinal cord causing weakness, coordination, balance difficulties, and other problems)

  • Other infections of the brain

  • Phenylketonuria (inability to break down the amino acid phenylalanine)

  • Traumatic brain injury

  • Tumors of the brain

  • Vascular disease including inflammation of the blood vessels

Other causes of seizures

Seizures can be caused by a variety of other circumstances including:

Serious or life-threatening causes of seizures

Seizures may be a symptom of a serious or life-threatening condition that should be evaluated immediately in an emergency setting. These include:

When should you see a doctor for seizures?

Anyone who has a seizure for the first time should seek immediate medical care.

For someone with epilepsy, make an appointment with your doctor if your seizures are increasing or you have new seizure symptoms. Call 911 or go to your nearest emergency room for a seizure when:

  • Another seizure happens very soon afterwards.

  • It lasts for five minutes or longer.

  • You are pregnant.

  • You are with someone who does not regain consciousness or breathing after a seizure.

  • You have a high fever, signs of heat exhaustion, or diabetes.

  • You sustained an injury during the seizure.

How do doctors diagnose the cause of seizures?

To diagnose the cause of your seizures, your doctor will ask you several questions about your seizures including:

  • Do you remember the seizure?

  • What happened during the seizure or what did people tell you happened?

  • What happened and how did you feel before the seizure?

  • How did you feel after the seizure?

  • Is this your first seizure?

  • Do you have a family history of seizures or epilepsy?

  • Have you had any recent head injuries?

  • Do you use alcohol or recreational drugs?

  • What other medical conditions do you have?

  • What medications are you taking?

Your doctor will also perform a physical exam, focusing on your nervous system, behaviors, and mental function. Diagnosing the cause of seizures involves testing as well. Your doctor will use various tests to rule out medical conditions and to determine if other seizures are likely. Testing may include:

  • Blood tests to check your blood sugar and electrolyte levels, alcohol or drug levels, liver and kidney function, and to look for signs of infection or genetic conditions

  • EEG (electroencephalogram), which records the electrical activity in your brain

  • Imaging exams of your brain, including CT (computerized tomography) scan, MRI (magnetic resonance imaging), PET (positron emission tomography), and SPECT (single-photon emission computerized tomography) to examine for any identifiable causes to explain seizure activity

  • Lumbar puncture to take a sample of cerebrospinal fluid (CSF) to check for signs of infection

It is not always possible to diagnose an underlying cause or condition. If the problem persists and your provider is unable to determine a cause, seeking a second opinion may give you more information and answers.

What are the treatments for seizures?

Not every seizure requires treatment. Sometimes, a seizure is an isolated incident and is not likely to recur. If you do have another seizure or your doctor diagnoses epilepsy, treatment may be necessary. The goal of treatment is to prevent seizures with the least amount of treatment side effects.

Treatment options for seizures may include:

  • Medications are the most common treatment for seizures. They help control abnormal electrical brain activity and prevent muscle spasms. There are several anti-seizure medicines. Some work better for certain types of seizures and they have various side effects. Finding the right one and the right dose for you can take some trial and error. 

  • Diet therapy can help with refractory seizures in combination with medications. The main approach is a ketogenic diet that is high in fat and low in carbohydrates. Because this is a difficult diet, some people may see a benefit with a less strict diet, such as a modified Atkins diet or a low glycemic index diet.

  • Electrical stimulation with implants that interfere with the abnormal electrical activity in the brain

  • Surgery may be an option if other treatments fail and the seizures originate from one identifiable area of the brain. There are several types of surgery that remove, destroy or disconnect the area of the brain causing the seizures.

People living with epilepsy may also benefit from counseling or cognitive behavioral therapy. While it will not control the seizures, it can help people cope with the challenges of the condition.

Home remedies for seizures

Home remedies will not treat seizures. But there are several lifestyle habits that may help prevent seizures and promote health and safety including:

  • Exercise regularly.

  • Get enough sleep each night. Lack of sleep can be a trigger for seizures.

  • Limit alcohol, nicotine and stress.

  • Stay hydrated.

  • Take steps to avoid injury, including padding sharp corners in your home, showering instead of bathing, and using a buddy system near water. Wear a helmet during sports and other physical activities.

  • Wear medical alert jewelry so people know how to help you in the event of a seizure.

What are the potential complications of seizures?

Seizures can range from mild and spontaneously resolving to serious and chronic. Because seizures involve bouts of unconsciousness, it is possible to undergo an injury during a seizure. Some seizures can be due to serious diseases, and failure to seek treatment can result in serious complications and permanent damage.

Once the underlying cause is diagnosed, it is important for you to follow the treatment plan you and your healthcare professional design specifically for you to reduce the risk of potential complications including:

  • Brain damage

  • Damage to your tongue or mouth due to biting during seizure

  • Injury during seizure

  • Pulmonary aspiration (inhaling food, liquids, blood, vomited material, or other substances into lungs)

  • Status epilepticus (recurrent seizures without recovery)

  • Sudden death from heart arrhythmia
Was this helpful?
  1. Dietary Therapies. Epilepsy Foundation. FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013.
  2. Epilepsy Information Page. National Institute of Neurological Disorders and Stroke.
  3. Focal Seizures. Johns Hopkins University.
  4. Generalized Seizures. Johns Hopkins University.
  5. Seizures. Mayo Foundation for Medical Education and Research.
  6. Seizures. MedlinePlus, National Library of Medicine National Institutes of Health.
  7. Types of Seizures. Centers for Disease Control and Prevention.
  8. Types of Seizures. Epilepsy Foundation.
  9. Types of Seizures. Johns Hopkins University.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jul 21
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