An eating disorder is a mental illness defined by a persistent disturbance in eating behavior that significantly impairs physical health or day-to-day functioning. That disturbance can look very different from person to person: severely restricting food, eating large amounts in a short period, purging after meals, or avoiding entire categories of food due to sensory issues or fear of negative consequences. What ties these conditions together is that the relationship with food or body image has become disruptive enough to cause real harm.
Eight distinct conditions currently fall under the eating disorder umbrella, and they affect people of all ages, genders, and body sizes. Eating disorders carry the second-highest mortality rate of any psychiatric illness, behind only opioid addiction.
The Clinical Definition
The formal psychiatric definition comes from the DSM-5-TR, the diagnostic manual used by mental health professionals in the United States and many other countries. It defines feeding and eating disorders as a “persistent disturbance of eating or eating-related behavior that results in the altered consumption or absorption of food and that significantly impairs physical health or psychosocial functioning.”
Two parts of that definition matter. First, the behavior has to be persistent, not a single skipped meal or one episode of overeating. Second, it has to cause meaningful harm, either to the body or to a person’s ability to function socially, at work, or in relationships. A person who occasionally eats past the point of comfort does not have an eating disorder. A person who regularly loses control over eating, feels intense shame afterward, and withdraws from social situations because of it may.
Types of Eating Disorders
The DSM-5-TR recognizes eight feeding and eating disorders. The three most widely known are anorexia nervosa, bulimia nervosa, and binge eating disorder, but the others are equally serious.
Anorexia Nervosa
Anorexia involves restricting food intake to the point of maintaining a significantly low body weight, combined with an intense fear of gaining weight and a distorted perception of one’s own body. People with anorexia often cannot see how thin they’ve become, or they acknowledge the weight loss but don’t recognize it as dangerous. The disorder has two subtypes: a restricting type, where weight loss comes from dieting, fasting, or excessive exercise, and a binge-purge type, where episodes of eating followed by vomiting or laxative use also occur.
Bulimia Nervosa
Bulimia is characterized by repeated cycles of eating large amounts of food in a short time (bingeing) followed by efforts to prevent weight gain, such as self-induced vomiting, misuse of laxatives, fasting, or extreme exercise. Unlike anorexia, people with bulimia are often at a normal weight or slightly above, which can make the disorder harder to spot from the outside. The bingeing and purging must occur at least once a week over three months to meet the diagnostic threshold.
Binge Eating Disorder
Binge eating disorder, or BED, is the most common eating disorder. It involves recurrent episodes of eating unusually large amounts of food while feeling a loss of control, but without the purging or compensatory behaviors seen in bulimia. Episodes happen at least once a week for three months. People with BED often eat rapidly, eat when not physically hungry, eat alone out of embarrassment, and feel disgusted or deeply guilty afterward.
ARFID
Avoidant/restrictive food intake disorder is not driven by concerns about body weight or shape. Instead, a person with ARFID avoids food based on its sensory qualities (texture, smell, appearance), a fear of choking or vomiting, or a general lack of interest in eating. The avoidance is severe enough to cause nutritional deficiency, significant weight loss, or dependence on supplements. ARFID is more commonly diagnosed in children but occurs in adults as well.
OSFED
Other specified feeding or eating disorder applies when someone shows many symptoms of anorexia, bulimia, or binge eating disorder but doesn’t meet every criterion for a full diagnosis. For example, a person might restrict food severely and fear weight gain but remain at a technically normal weight, or someone might binge and purge but less frequently than once a week. OSFED is not a “mild” diagnosis. It is a serious, potentially life-threatening condition that requires the same level of attention as any other eating disorder.
Pica, Rumination Disorder, and UFED
Pica involves persistently eating non-food substances like dirt, chalk, or paper. Rumination disorder involves repeatedly regurgitating food after eating, then re-chewing, re-swallowing, or spitting it out. Unspecified feeding or eating disorder (UFED) is used when a clinician determines an eating disorder is present but doesn’t specify which one, often in emergency settings where a full assessment hasn’t been completed.
What Causes Eating Disorders
No single factor causes an eating disorder. These conditions arise from a combination of genetic, biological, psychological, and social influences. People with a parent or sibling who had an eating disorder are at higher risk, suggesting a hereditary component. Changes in brain chemistry also appear to play a role, though the exact mechanisms aren’t fully understood.
Psychological traits like perfectionism, anxiety, and low self-esteem increase vulnerability, as do life experiences such as trauma, bullying, or growing up in an environment that places high value on thinness. Cultural pressure around body image contributes, but eating disorders occur across all cultures and demographics. They are not a lifestyle choice or a phase.
Physical Consequences
Eating disorders affect nearly every organ system. The specific damage depends on the type of disorder and how long it has gone untreated.
Anorexia takes a heavy toll on the heart, causing low blood pressure, a dangerously slow pulse, and structural damage to the heart muscle. Prolonged malnutrition thins the bones, leading to osteoporosis that may not be fully reversible even after weight restoration. Severe constipation and other digestive problems are common.
Bulimia causes a different set of complications. Repeated vomiting erodes tooth enamel, inflames the throat, and swells the salivary glands along the jaw. The more dangerous consequence is electrolyte imbalance: purging depletes sodium, potassium, and calcium to levels that can trigger a stroke or cardiac arrest. Chronic acid reflux and other gastrointestinal damage are also typical.
Binge eating disorder increases the risk of obesity-related conditions, including type 2 diabetes, high blood pressure, and cardiovascular disease. Across all eating disorders, suicide is one of the leading causes of death. Roughly 31% of people with anorexia, 23% with bulimia, and 23% with binge eating disorder have attempted suicide at some point.
How Eating Disorders Are Identified
Screening often begins with simple questionnaires. One widely used tool, the SCOFF, consists of just five questions designed to flag potential eating disorders in the same way the CAGE questionnaire screens for alcohol problems. A positive screen doesn’t confirm a diagnosis but signals the need for a more thorough evaluation.
A full assessment typically involves a detailed history of eating behaviors, thoughts about food and body image, physical symptoms, and mental health. Blood tests check for electrolyte imbalances, nutritional deficiencies, and organ function. In many cases, the person’s own account of their eating patterns is the most important diagnostic information, which is why honest conversation with a provider matters more than any single test.
Treatment Approaches
Treatment almost always combines psychological therapy with nutritional support, and sometimes medication. The specific approach depends on the disorder and its severity.
Enhanced cognitive behavioral therapy (CBT-E) is one of the most effective treatments for bulimia and binge eating disorder. It works by first stabilizing eating patterns, then addressing the distorted thoughts about food, weight, and self-worth that drive disordered behavior. Treatment typically unfolds over 20 sessions, though more complex cases take longer.
Family-based treatment is the leading approach for adolescents with anorexia. Parents take an active role in restoring their child’s nutrition and weight, gradually handing control back as the teen develops healthier habits. This model treats the family as part of the solution rather than part of the problem.
Nutritional rehabilitation is a core component regardless of the disorder. The goals are straightforward: reaching a weight that’s healthy for your individual body, establishing consistent meal patterns of at least three meals and one to two snacks daily, and learning to eat flexibly rather than by rigid rules. For people who have been severely malnourished, this process requires medical monitoring because refeeding too quickly can itself be dangerous.
Recovery timelines vary widely. Some people see significant improvement within months of starting treatment. Others cycle through periods of relapse and recovery over years. Full recovery is possible at any stage, even after decades of illness, but earlier intervention consistently leads to better outcomes.