How Many People Die From Seizures and Why?

Epilepsy-related deaths are far more common than most people realize. In the United States alone, epilepsy contributes to tens of thousands of deaths each year, and long-term studies show that people with epilepsy die at roughly twice the rate of the general population even when the majority achieve lasting seizure control. The causes range from sudden cardiac and respiratory failure during or after a seizure to drowning, status epilepticus, and suicide. Many of these deaths go unrecognized on death certificates, meaning the true toll is almost certainly higher than official counts suggest.

Overall Mortality in Epilepsy

A landmark long-term follow-up study found that even though over 70% of patients eventually achieved lasting remission from seizures, the overall death rate in the epilepsy cohort was still about twice what would be expected in the general population. The standardized mortality ratio, which compares observed deaths to expected deaths, was 2.1. The risk was not spread evenly. People whose epilepsy stemmed from a prior brain injury like stroke or head trauma had a mortality ratio of 3.7, and those with seizures caused by congenital neurological conditions had dramatically higher rates. Interestingly, people whose epilepsy had no identifiable structural cause did not have a meaningfully elevated death rate compared to the general population.¹

This pattern matters because it tells you that seizures themselves are only part of the story. Much of the excess mortality in epilepsy comes from the underlying brain condition that caused the seizures in the first place. A person who develops epilepsy after a stroke faces risks from both ongoing seizure activity and the vascular disease that triggered it. Separating “deaths from seizures” from “deaths with seizures” is one of the central challenges in understanding this topic.

SUDEP, the Leading Direct Cause

Sudden unexpected death in epilepsy, known as SUDEP, is the single most important seizure-related cause of death. It refers to the sudden, unexpected death of a person with epilepsy where no other cause is found at autopsy. SUDEP is rare in people with well-controlled seizures, occurring at a rate of about 0.35 per 1,000 person-years in newly diagnosed patients. But the risk climbs steeply with seizure severity. In people with chronic, drug-resistant epilepsy, the rate jumps to 1 to 2 per 1,000 person-years, and in the most severe cases it reaches 3 to 9 per 1,000.²

An American Academy of Neurology practice guideline put the risk in children with epilepsy at about 0.22 per 1,000 patient-years, rising to 1.2 per 1,000 patient-years in adults.³ The peak age range for SUDEP falls between 20 and 40, which makes it especially devastating because it disproportionately strikes young adults.²

What Actually Happens in the Body During SUDEP

For years, researchers assumed SUDEP was primarily a cardiac event. That view has shifted. Monitoring of patients who died in hospital epilepsy units has revealed that most SUDEP cases involve postictal central apnea, meaning the brain’s breathing center shuts down after a seizure and never restarts.⁴ In one well-documented near-SUDEP case, a 20-year-old woman had a convulsive seizure lasting under a minute, then stopped breathing entirely. Resuscitation was successful, and evaluation afterward showed no airway obstruction or lung problems. Her breathing center had simply stopped firing.⁵ This kind of apnea often goes unnoticed because breathing is not routinely monitored during seizures in most settings.⁶

Cardiac mechanisms play a secondary but real role. People with drug-resistant epilepsy frequently show abnormalities in heart rhythm during seizures. One long-term cardiac monitoring study of epilepsy patients recorded over 6,400 heart tracings and found heart rate changes during seizures in about three-quarters of patients. Most of the time this was just a fast heart rate, but some patients developed dangerously slow rhythms or long pauses that required permanent pacemaker implantation. Five patients in that study, roughly 2.6%, died suddenly during the follow-up period.⁷ A separate report documented a patient whose heart developed a fatal arrhythmia after a cluster of generalized convulsive seizures, preceded by a surge in parasympathetic nervous activity and prolonged brain suppression after the seizures ended.⁸ Dangerous QT interval prolongation during seizures has been observed in about 16% of seizures in people with drug-resistant epilepsy, which could set the stage for fatal ventricular arrhythmias.⁹

In practice, SUDEP probably involves a cascade: a generalized convulsive seizure suppresses both the brain’s breathing center and the autonomic systems that regulate heart rhythm. If no one is present to intervene, the combination can be lethal within minutes.

Status Epilepticus

When a seizure does not stop on its own or when seizures occur in rapid succession without recovery between them, the condition is called status epilepticus. It is a medical emergency and carries significant mortality. A large study of nearly 25,000 patients with status epilepticus found that about 7.5% died in the hospital. Another 7.7% died within 30 days of discharge, and roughly 20% died in the longer term after that. The leading causes of in-hospital death were complications of the status epilepticus itself, accounting for about 46% of deaths, followed by the underlying seizure at about 20% and pre-existing medical conditions at about 15%.¹⁰

The prognosis depends heavily on what triggered the prolonged seizure. When status epilepticus occurs as a complication of an acute stroke, the 10-year mortality rate can exceed 76%, compared with about 30% for shorter acute seizures after stroke and just 11% in stroke survivors who never had a seizure at all.¹¹

Acute Symptomatic Seizures and Short-Term Death Risk

Not every seizure means epilepsy. A seizure triggered by an acute event like a high fever, a stroke in progress, a brain infection, or severe alcohol withdrawal is categorized as an acute symptomatic seizure. These carry a sharply different risk profile from unprovoked seizures. People experiencing a first acute symptomatic seizure were nearly nine times more likely to die within 30 days compared to people who had a first unprovoked seizure, after accounting for age, sex, and whether the seizure became prolonged.¹²

The reassuring flip side: among people who survived the first 30 days, the long-term mortality risk was no different between the two groups. And people with an acute symptomatic seizure were about 80% less likely to go on to develop epilepsy compared with those whose first seizure was unprovoked.¹² So the danger from an acute symptomatic seizure is mostly front-loaded into the days surrounding the triggering event, driven by the severity of whatever caused the seizure rather than the seizure itself.

Drowning and Accidents

Seizure-related accidental deaths are a significant but often overlooked contributor. Drowning is the starkest example. A study of children with epilepsy found that their relative risk of drowning in a bathtub was 96 times that of children without epilepsy. Even in a swimming pool, the relative risk of drowning was about 23 times higher.¹³ The mechanism is straightforward: a seizure in water leaves a person unable to keep their head above the surface, and even a brief lapse in consciousness can be fatal in a bathtub. Adults with epilepsy face similar risks, though comprehensive drowning statistics for this group are not well tracked, and survival after immersion events in the bath is often not captured in the data.¹⁴

Motor vehicle accidents related to seizures are less common than people tend to assume. An analysis of U.S. crash data from the mid-1990s found that only about 0.2% of motor vehicle accidents were seizure-related, and the fatal crash rate for the general population was actually about 2.6 times higher than for people with epilepsy. This likely reflects the effect of driving restrictions that keep many people with active seizures off the road. That said, the relative risk of a fatal crash for someone with seizures was about 2.3 times higher than for someone with cardiovascular disease and about 4.6 times higher than for someone with diabetes, which provides some context for why driving regulations specifically target seizure disorders.¹⁵

Suicide and Psychiatric Factors

Suicide is a real and underappreciated contributor to excess mortality in epilepsy. Suicidal thoughts and attempts are significantly more common in people with epilepsy than in the general population, driven by a tangled relationship between epilepsy, depression, anxiety, and the psychosocial burden of living with a chronic, stigmatized condition.¹⁶ The relationship appears to be bidirectional: depression increases seizure risk, and seizures worsen depression, creating a feedback loop that can be hard to break.

The risk is particularly elevated in people who have both epilepsy and psychogenic nonepileptic seizures (events that resemble seizures but are not caused by abnormal electrical brain activity). A study found that people with both conditions had about 2.5 times the odds of a hospitalization for a suicide attempt compared to people with epilepsy alone.¹⁷ This is a population that clinicians sometimes struggle to manage, and the psychiatric burden tends to be severe.

Why Medication Adherence Is a Life-or-Death Issue

Skipping or tapering off seizure medications without medical guidance is one of the most preventable risk factors for seizure-related death. A data linkage study found that a declining pattern of medication adherence, seen in about a quarter of patients, was associated with more than eight times the risk of SUDEP.¹⁸ The mechanism is not mysterious: missed doses lead to more seizures, and more seizures mean more opportunities for SUDEP, status epilepticus, and accidents. A broader review confirmed that the longer non-adherence persists, the more the SUDEP risk compounds.¹⁹

A large population-based cohort study examining 30-day sudden death risk in epilepsy identified poor medication adherence (specifically, possessing less than half of prescribed medication) as a significant factor, alongside older age, intensive care admission, chronic kidney disease, and psychotic disorders.²⁰ People sometimes stop taking their medications because they feel fine, because of side effects, or because of cost. Each of these reasons is understandable, but the data make clear that abrupt discontinuation or gradual drift away from a medication regimen carries serious risk.

Nocturnal Seizures and Sleeping Position

A disproportionate number of SUDEP cases happen at night. People who died of SUDEP were far more likely to have had nocturnal convulsive seizures: about 77% of SUDEP cases involved nocturnal convulsions, compared with 33% of living controls with epilepsy.²¹ The likely reason is that no one is awake to notice the seizure, reposition the person, or call for help if breathing stops.

Sleeping face-down adds an extra layer of danger. A study examining body position in SUDEP cases found a strong association between the prone (face-down) position and death. After a generalized convulsive seizure, a person who is unresponsive may end up face-down and be unable to turn over. The combination of suppressed breathing reflexes and a blocked airway from the pillow or mattress can turn a survivable event into a fatal one.²² This is one of the few modifiable risk factors for SUDEP, and some clinicians now advise patients to avoid sleeping face-down when possible.

Dravet Syndrome and Pediatric Genetic Epilepsy

Certain childhood epilepsy syndromes carry especially high mortality. Dravet syndrome, a severe genetic epilepsy that begins in infancy, illustrates how devastating the combination of frequent seizures and early onset can be. In one cohort, 17 patients died at a median age of just seven years. Ten of those deaths were classified as SUDEP, four were from status epilepticus, two were drownings, and one was from asphyxia.²³ The full range of seizure-related death mechanisms shows up in this single population: sudden death, prolonged seizures, and accidents all contribute. Children with severe epilepsy syndromes need heightened supervision around water, close medical management, and honest conversations with families about SUDEP risk.

Why Seizure Deaths Are Undercounted

The true number of seizure-related deaths is almost certainly higher than what death certificates reflect. The National Association of Medical Examiners has pointed out that the physical findings typically associated with seizures, like tongue or lip bites, are frequently absent and have variable diagnostic specificity. When a person with epilepsy is found dead and there are no obvious signs of a seizure, the death may be attributed to an unknown cause or to a pre-existing heart condition rather than to SUDEP.²⁴ This underreporting means that policy decisions, research funding, and public awareness about seizure-related deaths are all based on numbers that understate the problem.

The Treatment Gap in Low-Income Countries

Access to epilepsy treatment varies enormously around the world, and where treatment is unavailable, seizure-related mortality is higher. A systematic review of the epilepsy treatment gap in developing countries estimated that about 56% of people with epilepsy were not receiving appropriate treatment. The gap was widest in rural areas, where roughly 73% of people went untreated compared with about 47% in urban settings. Cost was universally cited as a barrier, but the biggest single factor was a shortage of trained healthcare workers.²⁵ When people with epilepsy cannot access inexpensive medications that would control their seizures, every risk factor discussed in this article is amplified: more uncontrolled seizures, more SUDEP, more status epilepticus, more drownings, and more preventable deaths.

Surgery and Its Effect on Long-Term Survival

For people whose seizures do not respond to medication, epilepsy surgery can be life-saving in a literal sense. A population-based study found that surgery was associated with a 30% reduction in all-cause mortality, and the benefit appeared to persist and possibly even increase after 15 years of follow-up. Among operated patients, those who continued to have seizures had about twice the risk of dying and about 3.5 times the SUDEP risk compared with those who became seizure-free after surgery.²⁶ A large cohort study confirmed that overall mortality in surgically treated patients did not exceed that of the general population over the long term, reinforcing the value of early surgical evaluation when medications fail.²⁷

The evidence here is genuinely encouraging but carries an important caveat noted by earlier reviews: seizure freedom after surgery does track with lower mortality, yet the range of outcomes across studies has been inconsistent enough that researchers are cautious about making universal promises.²⁸ Still, the direction of the evidence is clear: stopping seizures reduces the risk of dying from them.

Seizure Detection Devices and Nighttime Monitoring

Because so many SUDEP deaths happen at night when no one is watching, there has been a push to develop wearable or bedside devices that can detect convulsive seizures and alert a caregiver. At least five seizure detection devices have been validated in late-stage studies for detecting convulsive seizures, achieving sensitivity of at least 90% with acceptable false-alarm rates.²⁹ Long-term use of these devices in home settings has been shown to improve the accuracy of seizure diaries and reduce seizure-related injuries, though direct evidence that they prevent SUDEP is still lacking.³⁰

The logic is strong even if the definitive proof is not yet in hand: if postictal apnea and prone positioning are major SUDEP mechanisms, then having someone alerted within seconds to reposition the person and stimulate breathing should reduce risk. Clinical experience supports this reasoning, and many epilepsy specialists already recommend detection devices for high-risk patients, particularly those who sleep alone and have frequent nighttime convulsive seizures.²⁹

1
PubMed Central. Mortality in Epilepsy
2
PubMed. Sudden unexpected death in epilepsy: a review of incidence and risk factors
3
PubMed. Practice guideline summary: Sudden unexpected death in epilepsy incidence rates and risk factors
4
PubMed Central. Sudden unexpected death in epilepsy: Respiratory mechanisms
5
PubMed. Postictal central apnea as a cause of SUDEP: evidence from near-SUDEP incident
6
Seizure. Central apnea at complex partial seizure onset
7
Heart Rhythm. Cardiac arrhythmias and sudden unexpected death in epilepsy: Results of long-term monitoring
8
PubMed. Heart rate variability analysis indicates preictal parasympathetic overdrive preceding seizure-induced cardiac dysrhythmias leading to sudden unexpected death in a patient with epilepsy
9
PubMed Central. Sudden death in epilepsy: the overlap between cardiac and neurological factors
10
Epilepsy & Behavior. Causes of death in patients with status epilepticus
11
PubMed Central. Association of Mortality and Risk of Epilepsy With Type of Acute Symptomatic Seizure After Ischemic Stroke and an Updated Prognostic Model
12
Epilepsia. Is a first acute symptomatic seizure epilepsy? Mortality and risk for recurrent seizure
13
PubMed. Epilepsy as a risk factor for submersion injury in children
14
British Journal of Neuroscience Nursing. Reducing the risk of drowning in the bath for people with epilepsy through product development
15
PubMed Central. Injuries in epilepsy: a review of its prevalence, risk factors, type of injuries and prevention
16
PubMed Central. Suicidality and epilepsy: a complex relationship that remains misunderstood and underestimated
17
PubMed Central. Increased suicide attempt risk in people with epilepsy in the presence of concurrent psychogenic nonepileptic seizures
18
PubMed. Adherence patterns in antiseizure medications influencing risk of sudden unexplained death in epilepsy: A data linkage study using dispensed prescriptions
19
PubMed Central. Antiseizure Medications and Sudden Unexpected Death in Epilepsy: An Updated Review
20
PubMed Central. The 30-Day Risk of Sudden Death in Patients With Epilepsy: A 10-Year Population-Based Cohort Study
21
PubMed. Nocturnal supervision and SUDEP risk at different epilepsy care settings
22
PubMed Central. Association of prone position with sudden unexpected death in epilepsy
23
Epilepsy Research. Mortality in Dravet syndrome
24
PubMed Central. National Association of Medical Examiners position paper: Recommendations for the investigation and certification of deaths in people with epilepsy
25
PubMed Central. The epilepsy treatment gap in developing countries: a systematic review of the magnitude, causes and intervention strategies
26
Journal of Neurology, Neurosurgery & Psychiatry. Reduced long-term mortality after successful resective epilepsy surgery: a population-based study
27
PubMed Central. Long‐term survival after adult epilepsy surgery: Mortality and predictors in a large cohort
28
Brain. Long-term outcomes in epilepsy surgery: antiepileptic drugs, mortality, cognitive and psychosocial aspects
29
PubMed. Update review on SUDEP: Risk assessment, background & seizure detection devices
30
PubMed Central. Seizure Detection Devices