Sudden Unexpected Death in Epilepsy (SUDEP) is said to occur when a person with epilepsy dies unexpectedly and was previously in their usual state of health. The death is not known to be related to an accident or seizure emergency such as status epilepticus. When an autopsy is done, no other of cause of death can be found.

  • Each year, more than 1 in 1,000 people with epilepsy die from SUDEP.
  • People with poorly controlled epilepsy are at greatest risk of dying from SUDEP.
  • SUDEP takes more lives annually in the United States than sudden infant death syndrome (SIDS).
  • People with only absence or myoclonic seizures are not known to have increased risk for sudden death.

No one knows what causes SUDEP, but many areas are being looked at. SUDEP occurs most often at night or during sleep when the death is not witnessed, leaving many questions unanswered. There may be evidence that a person had a seizure before dying, but this isn’t always the case.

Current research into the possible causes of SUDEP focuses on problems with breathing, heart rhythm and brain function that occur with a seizure.

  • Breathing: A seizure typically may cause a person to briefly stop breathing (apnea). If these breathing pauses last too long, they can reduce the amount of oxygen that gets to the heart and the brain. A lack of oxygen can be life threatening if not treated immediately. Also, a person’s airway may sometimes get blocked blocked during a convulsive seizure, leading to suffocation (inability to breathe).
  • Heart Rhythm: Rarely, a seizure may cause a dangerous heart rhythm or cardiac arrest.
  • Brain Function Seizures may suppress or interfere with the function of vital areas in the brainstem. These areas are responsible for breathing and heart rate as well as other important body functions. As a result, changes in brain function could cause dangerous breathing and heart rate changes.
  • Others: SUDEP may result from more than one cause, or from a combination of breathing difficulty, abnormal heart rhythm and changes in brain function. Or, it may result from factors researchers have yet to discover.

For a more details, visit our "How SUDEP Occurs" section.

The greatest risk factor for SUDEP is having tonic clonic seizures (grand mal).

People with night time seizures may also be at higher risk.

Missing medications or not taking seizure medicines as prescribed, because it can lead to more seizures, may also put people at higher risk for SUDEP.

The answer depends on how severe the epilepsy is and the type of seizures she is having. While some studies found that rates of SUDEP are lower in children, others found rates similar to those seen in adults.

The best way to prevent SUDEP is to have as few seizures as possible.

  • Get the best seizure control possible. This may involve actions such as:
    • Taking medication regularly and at the right dose.
    • Visiting your health care team regularly, especially if seizures are not controlled.
    • If medicines do not work, consider other treatment options such as epilepsy surgery, devices, or dietary therapy.
  • Take good care of yourself or your loved one. Eat well, get enough rest and regular exercise, avoid drinking too much alcohol or using recreational drugs, and minimize stress when possible.
  • Be aware of and avoid any potential seizure triggers whenever possible. Keep a record of things that occurred before a seizure (such as illness, tiredness, stress, missing medications, and where and when the seizure occurred).
  • Talk to your doctor about having your heart checked (cardiac evaluation) to rule out any heart problems. This is especially important if the diagnosis of epilepsy is not certain or the seizures are not controlled.
  • Be seizure safe. Make sure family and co-workers know what to do for seizure first-aid, take extra precautions around water, including swimming and bathing.

Learn more about preventing SUDEP.

Often there are signs that a person had a seizure before dying, but this isn’t always the case. While a seizure is not a requirement for SUDEP to be diagnosed, recent studies suggest most SUDEP are likely seizure-related.

There are some studies that suggest genetic factors may play a role, but no definite information is available at this time. Several research efforts are looking into genetics and SUDEP. Read more about the Search for Genetic Risk Factors for SUDEP.

Yes! If your doctor has not spoken to you about the health risks associated with epilepsy, you should ask him or her about SUDEP.

Questions to ask may include:

  • What risks do I or my family member have for SUDEP?
  • What can we do to lessen the risk of SUDEP?

There is no data to support the use of these pillows to prevent SUDEP. They are made to help people who are at risk for suffocation. Talk to your health care provider about any possible benefits of these for you or your loved one.

Learn more about using special pillows.

Having someone available at night who is able to provide help during and after a seizure may be one way to limit SUDEP. For example, a person could help provide first aid, keep the person on their side if they had a generalized seizure, and reposition them after the seizure so their breathing isn’t blocked.

However this is often not practical or desired, and more scientific evidence is needed to prove that it is effective in preventing SUDEP.

Several devices are being developed to detect seizures and alert caregivers when a seizure occurs. However, the devices may not alert you that your loved one has stopped breathing. Whether these devices can prevent SUDEP remains unknown.

Learn more about the role of seizure alerts.

If you have recently lost a loved one to SUDEP, contact the North American SUDEP Registry (NASR) and participate in their study to help find the causes of SUDEP. The multicenter NASR provides clinical data, DNA and brain tissue for the scientific community to study. For more information call 855-432-8555 or email; or contact Dr. Devinsky at 646-558-0801 or email

The Ion Channels in Epilepsy study at Baylor College of Medicine is also accepting participants. This study is trying to identify genetic risk factors that may make a person with epilepsy more likely to die suddenly. For more information, contact Dr. Goldman at 713-798-0980 or email

Contact your local Epilepsy Foundation or any of the organizations with websites listed below.

Authored By:

Daniel Friedman MD
Joseph I. Sirven MD

on Wednesday, March 19, 2014

Reviewed By:

Alison Kukla MPH

on Monday, April 04, 2022


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