Can Eating Disorders Cause Seizures?

Eating disorders can cause seizures, and the pathways connecting the two are more varied than most people realize. Starvation, purging, and extreme fluid behaviors all disrupt the body’s chemistry in ways that can push the brain past its threshold for abnormal electrical activity. A study in the International Journal of Eating Disorders found that among people with eating disorders who experienced seizures, roughly one in ten cases was tied to electrolyte abnormalities or dangerously low blood sugar. But electrolytes are just one piece of a larger puzzle that includes medication side effects, nutritional collapse during recovery, and cardiac events that mimic seizures closely enough to fool clinicians.

How Disrupted Body Chemistry Triggers Seizures

The brain relies on a precise balance of minerals like sodium, potassium, calcium, magnesium, and phosphorus to transmit electrical signals between neurons. Eating disorders attack that balance from multiple directions. Repeated vomiting flushes potassium and chloride out of the body. Laxative abuse depletes sodium and magnesium. Severe restriction starves the body of all of these at once. When levels drop far enough, neurons start firing erratically, and the result can be a full seizure.

Blood sugar plays a parallel role. The brain runs almost exclusively on glucose, and prolonged fasting or extreme caloric restriction can cause blood sugar to plummet to dangerous levels. Hypoglycemia severe enough to trigger a seizure is a recognized complication of anorexia nervosa, and it tends to strike without much warning, especially overnight or after exercise. In the study that cataloged seizure causes in people with eating disorders, electrolyte abnormalities and hypoglycemia together accounted for about 11% of cases, while substance abuse or withdrawal accounted for nearly 19% and a pre-existing seizure disorder accounted for 12%.¹ That breakdown underscores that no single mechanism dominates. The seizure risk in eating disorders is cumulative, arising from whichever metabolic system breaks down first.

Water Intoxication and Extreme Fluid Behaviors

One of the less well-known seizure triggers in eating disorders is excessive water drinking. Some people with anorexia nervosa drink large volumes of water to suppress hunger, to manipulate their weight before clinical weigh-ins, or as part of compulsive rituals. When water intake vastly outpaces the kidneys’ ability to excrete it, sodium levels in the blood drop precipitously. The resulting condition, called hyponatremia, can progress from confusion and lethargy to full-blown seizures and loss of consciousness.²

In one reported case, a teenage girl with anorexia nervosa was admitted to a pediatric intensive care unit after drinking extreme quantities of water. She developed generalized tonic-clonic seizures and required sedation, intubation, and an infusion of concentrated saline to bring her sodium levels back up. Even after an initial bolus of hypertonic saline, her sodium remained dangerously low, and the correction had to be continued carefully to avoid a separate neurological complication from raising sodium too fast.³ Cases like these are not the norm, but compulsive water drinking is more common in anorexia than many clinicians appreciate, and it can escalate quickly.

Why Recovery Itself Can Be Dangerous

One of the cruelest ironies of severe eating disorders is that the refeeding process, the medical reintroduction of nutrition after prolonged starvation, carries its own seizure risk. When someone who has been starving begins to eat again, insulin surges in response to incoming calories, and this drives phosphorus, potassium, and magnesium out of the blood and into cells. The sudden drop in phosphorus levels is especially dangerous. A review in Nutrition in Clinical Practice noted that patients undergoing refeeding can develop fluid and electrolyte disorders, especially low phosphorus, along with neurologic, cardiac, and neuromuscular complications.⁴

Refeeding syndrome is most likely to occur in the first several days of nutritional rehabilitation, and the risk is highest in patients with the most severe or prolonged restriction. This is why treatment protocols for anorexia nervosa start with cautious calorie levels and include close monitoring of blood chemistry. Seizures from refeeding are preventable when the process is managed properly, but they remain a real danger for anyone who resumes eating abruptly after a long period of starvation, especially outside of medical supervision.

Medications That Lower the Seizure Threshold

People with eating disorders are often prescribed psychiatric medications for co-occurring conditions like depression or anxiety, and some of these medications carry a seizure risk that is specifically elevated in malnourished patients. The most notable example is bupropion, marketed as Wellbutrin for depression and Zyban for smoking cessation. Bupropion is explicitly contraindicated in patients with a current or past history of bulimia nervosa or anorexia nervosa because the incidence of seizures is markedly increased in such patients.⁵

The reasons likely overlap. Bupropion lowers the seizure threshold on its own, and the electrolyte disturbances and nutritional deficits caused by an eating disorder lower it further. The combination pushes the risk beyond what would be expected from either factor alone. Despite the contraindication being well established, clinicians sometimes prescribe bupropion without fully screening for eating disorder history, or patients may not disclose the history. If you have an eating disorder or a history of one, this is worth flagging with any prescriber who suggests bupropion, because the seizure risk is not theoretical. Other medications can also lower the seizure threshold, including certain antipsychotics and even some anti-nausea drugs, but bupropion is the one with the most prominent warning specific to eating disorders.

Vitamin Deficiency and Brain Injury

Prolonged malnutrition doesn’t just deplete minerals. It starves the brain of vitamins it needs to function, and the neurological consequences can include seizures. Thiamine, also known as vitamin B1, is a case in point. When thiamine levels fall critically low, the result can be Wernicke encephalopathy, a neurological emergency that involves confusion, abnormal eye movements, and difficulty walking. A report in the American Journal of Case Reports described Wernicke encephalopathy occurring in a pediatric patient with a restrictive eating disorder and noted that it can be precipitated by nutritional imbalance, prolonged intravenous feeding, persistent vomiting, and anorexia nervosa.⁶

Wernicke encephalopathy is most famously associated with chronic alcohol use, so it’s frequently missed in patients with eating disorders, particularly younger ones. Clinicians may not think to check thiamine levels in a teenager who isn’t drinking. If left untreated, the condition can progress to permanent brain damage. Thiamine supplementation is inexpensive and effective when started early, which makes the missed diagnosis especially frustrating. Beyond thiamine, deficiencies in folate, B12, and other nutrients from chronic malnutrition can also contribute to neurological instability, although seizures from those deficiencies alone are less common.

When It Looks Like a Seizure but Isn’t

A complication that muddies the picture for both patients and doctors is that eating disorders can cause episodes that look exactly like seizures but are actually cardiac in origin. Severe potassium depletion, commonly caused by repeated vomiting or laxative abuse, can lengthen a particular interval on an electrocardiogram known as the QT interval. A prolonged QT interval makes the heart vulnerable to a type of arrhythmia that can cause sudden loss of consciousness with convulsive movements, closely mimicking a seizure.

A case reported in the International Journal of Cardiology described a young woman with anorexia who experienced recurrent episodes of convulsive loss of consciousness. She was initially diagnosed with epilepsy, but continuous heart monitoring revealed that her episodes were actually caused by a dangerous heart rhythm triggered by severe potassium depletion and compounded by a medication she was taking for gastrointestinal symptoms. Once the medication was stopped and her potassium normalized, the episodes disappeared entirely.⁷ The authors noted that syncope from cardiac arrhythmias is a condition often misdiagnosed as epileptic seizures. This distinction matters because the treatments are completely different: anti-seizure medications would not have fixed her heart rhythm, and missing the true cause left a potentially fatal arrhythmia untreated.

For anyone with an eating disorder who experiences episodes of fainting or convulsions, this is a reason to push for thorough cardiac evaluation rather than accepting a seizure diagnosis at face value. An electrocardiogram and sometimes extended heart monitoring can clarify whether the heart, the brain, or both are involved.

The Overlap Between Epilepsy and Eating Disorders

Separate from the metabolic seizures discussed above, there is a genuine overlap between epilepsy as a primary brain condition and eating disorders as psychiatric conditions. A study published in Epilepsia found that adolescents with epilepsy who also had an eating disorder were more likely to have co-occurring depression, anxiety, and suicidal thoughts than adolescents with only epilepsy or only an eating disorder.⁸ The reasons for this overlap are not fully understood, but some anti-seizure medications affect appetite and weight, which can feed into disordered eating patterns. Topiramate, for instance, often suppresses appetite and causes weight loss, while valproate tends to cause weight gain. Either effect can become entangled with body image concerns in vulnerable individuals.

The clinical takeaway is that someone with both conditions needs coordinated care. A neurologist managing seizures with a medication that causes weight loss may inadvertently reinforce restrictive eating. A psychiatrist treating an eating disorder may not realize that a new seizure is metabolic rather than a breakthrough from the patient’s epilepsy. These patients fall between specialties in a way that can delay appropriate treatment.

Substance Use as an Amplifying Factor

Eating disorders and substance use disorders co-occur at high rates, and substances introduce their own seizure risks on top of the metabolic instability already present. Alcohol withdrawal is one of the most common medical causes of seizures in general, and among people with eating disorders who experienced seizures, substance abuse or withdrawal was the single most common identifiable cause, accounting for nearly one in five cases.¹ Stimulant use, sometimes adopted as an appetite suppressant, also lowers the seizure threshold. When these substance effects layer onto a body already depleted of potassium, magnesium, and glucose, the combined risk is greater than either factor would be alone.

This is a particularly tricky area because patients with eating disorders sometimes do not disclose substance use to their treatment teams, and clinicians focused on the eating disorder may not screen aggressively for it. If seizures are occurring in someone with an eating disorder and the metabolic workup comes back relatively normal, substance use is worth investigating as a contributing cause.

Reversibility and What to Watch For

The encouraging news is that most of the organ damage caused by eating disorders, including the metabolic disruptions that lead to seizures, is reversible with time and appropriate medical care.⁹ Once electrolytes are stabilized, blood sugar is normalized, and nutritional rehabilitation is underway, the brain typically stops seizing. People who have had metabolic seizures from an eating disorder do not usually go on to develop epilepsy unless there was underlying brain damage or a separate predisposition.

That said, “reversible” assumes the person gets treatment before irreversible harm occurs. Severe or repeated episodes of low blood sugar can damage the brain. Profound and sustained hyponatremia from water intoxication can cause brain swelling. Untreated Wernicke encephalopathy can progress to permanent cognitive impairment. The window for reversibility is real, but it closes. For caregivers and clinicians, new-onset seizures or seizure-like episodes in someone with an eating disorder should be treated as a medical emergency rather than a psychiatric symptom, because the underlying metabolic cause may be life-threatening even if the seizure itself resolves quickly.

Practical Signals That Something Is Wrong

Seizures in eating disorders rarely arrive without warning, though the warning signs are easy to misread. Muscle cramps, tingling in the hands or around the mouth, heart palpitations, and unusual fatigue are all signs that electrolytes may be dropping into a dangerous range. Lightheadedness and brief “gray-outs” when standing can signal either low blood pressure or an impending cardiac event that might be mistaken for a seizure later. Excessive thirst or ritualistic water drinking in someone with anorexia should raise concern about the possibility of water intoxication and hyponatremia.

If you are supporting someone with an eating disorder, any episode involving loss of consciousness, convulsive movements, or sudden confusion warrants emergency medical evaluation. The priority is figuring out whether the event was a true seizure, a cardiac arrhythmia, or a hypoglycemic episode, because the treatment for each is different. Blood work, an electrocardiogram, and sometimes brain imaging are all part of that workup. What you should not do is wait to see if it happens again, because in the context of an eating disorder, the metabolic cause is likely still active and escalating.