Eating Disorders: Types, Symptoms, Causes, and Treatment

Author: Angela Bogdanova · Published: October 10, 2026 · Editorial Policy

Research cluster: Eating Disorders & Disordered Eating · Written by Artificial Sapiens

Eating disorders are serious mental health conditions involving persistent disturbances in eating or feeding, distressing thoughts or emotions, and effects on physical health, daily functioning, or development. They include anorexia nervosa, bulimia nervosa, binge-eating disorder, avoidant/restrictive food intake disorder (ARFID), and several other recognized conditions. They can affect people of every age, sex, gender, race, background, and body size. Many are treatable, and early evaluation improves the chance of addressing both psychological and medical harm. National Institute of Mental Health (NIMH)

This guide explains the main diagnoses and related behaviors, warning signs, what current research suggests about causes, how clinicians evaluate risk, and which treatments have evidence for particular conditions and age groups. It also explains why a screening score, a person's appearance, or a single unusual eating behavior cannot establish a clinical diagnosis.

What Are Eating Disorders?

In clinical practice, feeding and eating disorders are defined by patterns of behavior and associated psychological, nutritional, developmental, or functional consequences. Some involve intense concerns about weight or shape; others arise primarily from sensory sensitivities, fear of aversive consequences of eating, lack of interest in food, ingestion of nonfood substances, or repeated regurgitation. Understanding the pattern matters because anorexia, bulimia, binge-eating disorder, and ARFID require different diagnostic assessments and can call for different interventions. NIMH: Eating Disorders

The term disordered eating is broader than a formal diagnosis. It describes concerning patterns such as rigid food rules, repetitive dieting and restriction, distress around meals, loss-of-control episodes, or compensatory behaviors. A person may experience substantial impairment and medical consequences before meeting the full threshold for one named diagnosis. Diagnostic categories are used to organize clinical decisions; severity also requires attention to physiology, behavior, psychological distress, rate of change, and the person's developmental context.

Types of Eating Disorders and How They Differ

Anorexia nervosa

Anorexia nervosa involves restrictive energy intake leading to significantly low body weight in the context of age, development, and physical health, together with intense fear of weight gain or persistent behaviors that interfere with weight restoration and a disturbance in how weight or shape is experienced or evaluated. Clinicians recognize restricting and binge-eating/purging presentations; the latter may include episodes of binge eating or purging during the illness. Significant malnutrition can affect cardiovascular function, bones, cognition, growth, hormones, and mood. Anorexia can become life-threatening and warrants coordinated medical and psychological care. NIMH American Psychiatric Association practice guideline

Atypical anorexia nervosa

Atypical anorexia nervosa is a specified presentation within other specified feeding or eating disorder (OSFED). The person has the central features of anorexia nervosa but, despite significant weight loss, their weight is not below the diagnostic threshold for anorexia nervosa. A normal-range or higher-weight appearance cannot establish nutritional stability. The Society for Adolescent Health and Medicine states that medical and psychological complications in atypical anorexia can be as severe as those in anorexia nervosa; assessment considers vital signs, weight trajectory, rate of loss, symptoms, and laboratory findings. Society for Adolescent Health and Medicine (SAHM)

Bulimia nervosa

Bulimia nervosa is characterized by recurrent binge-eating episodes with a sense of loss of control, followed by recurrent inappropriate compensatory behavior intended to influence weight or shape. Body weight and shape exert an excessive influence on self-evaluation. People with bulimia often do not appear underweight. Repeated compensatory behaviors can produce dehydration, electrolyte disturbances, dental erosion, gastrointestinal injury, and dangerous heart-rhythm problems. Treatment addresses the cycle of dietary restraint, binge eating, compensatory behavior, and intense self-judgment rather than focusing on appearance. NIMH

Binge-eating disorder (BED)

Binge-eating disorder involves recurrent episodes of eating an objectively unusually large amount of food in a discrete period while feeling unable to control the episode, together with marked distress and associated behavioral features. Unlike bulimia nervosa, the disorder does not involve regular inappropriate compensatory behavior. BED can occur across body sizes, and weight alone does not identify it. Eating more than intended at a holiday meal, eating for comfort, or an isolated loss-of-control experience is not equivalent to a BED diagnosis. NIMH

Avoidant/restrictive food intake disorder (ARFID)

ARFID involves avoidance or restriction of food intake sufficient to cause clinically significant nutritional deficiency, weight or growth difficulties, dependence on nutritional supplements or enteral feeding, or pronounced psychosocial interference. Common pathways include sensory sensitivity to food, limited interest in eating, and fear of consequences such as choking or vomiting. The restriction is not primarily motivated by weight or shape concerns, which distinguishes ARFID from classic anorexia and bulimia presentations. Clinicians must also evaluate swallowing difficulties, gastrointestinal disorders, food allergy, and other medical explanations. NIMH SAHM

Other specified feeding or eating disorder (OSFED)

OSFED is a formal diagnostic category for clinically important symptoms that do not satisfy every criterion of another named feeding or eating disorder, when a clinician can explain why the complete threshold is not met. Examples include atypical anorexia nervosa, bulimia or binge-eating presentations of limited frequency or duration, purging disorder, and night eating syndrome. These presentations can still carry important psychological and medical risks. The label does not mean that the illness is mild or that care can be postponed. A complete assessment determines the predominant pattern and the most appropriate treatment approach. NICE NG69

Unspecified feeding or eating disorder (UFED)

UFED applies when clinically significant feeding or eating symptoms are present but there is insufficient information, or no specific reason is given, to assign a more precise category. It may be used in urgent or early assessments when fuller diagnostic information is still being gathered. UFED is a legitimate clinical classification rather than a self-diagnosis or a diagnosis made solely because someone cannot identify with online descriptions.

Pica and rumination disorder

Pica is a persistent pattern of eating nonnutritive, nonfood substances in a way that is developmentally inappropriate and not part of a culturally supported practice. Medical complications can include poisoning, intestinal obstruction, and infection, depending on the substances involved. Rumination disorder involves repeated regurgitation of food that may be rechewed, reswallowed, or expelled, in a pattern not attributable to a gastrointestinal or other medical condition. Both are recognized feeding and eating disorders, but assessment requires careful consideration of development, medical causes, and cultural context. American Academy of Pediatrics clinical report

Orthorexia and other emerging labels

Orthorexia nervosa is a research and clinical discussion term for a rigid, impairing preoccupation with eating in a manner perceived as healthy or pure. As of this article's publication, orthorexia is not an independent diagnosis in DSM-5-TR or ICD-11. An international Delphi study proposed consensus features but also documented limited evidence and unresolved classification questions. Another label sometimes used online may capture real distress without representing a separately validated disorder. The clinical task is to assess the actual behavior, impairment, medical status, and any established diagnosis rather than assign an internet label. Donini and colleagues, consensus study

Eating Disorder Symptoms and Early Warning Signs

Eating disorders often develop gradually. Signs can involve food, mood, physical health, relationships, and the person's response to disruption of eating routines. One sign may have several explanations, while combinations, persistence, distress, impairment, and change over time create a stronger reason for assessment. Some people conceal symptoms because of shame or fear of losing a coping strategy. Others may not recognize the seriousness of their symptoms while physically unwell.

Behavioral and emotional signs

Examples include increasingly inflexible food rules, skipping meals or avoiding shared meals, anxiety when routines change, repeated checking of food-related information, frequent preoccupation with weight or shape, secretive eating or episodes experienced as out of control, compensatory behaviors, food-related guilt, and distress that disrupts school, work, relationships, or leisure. In ARFID, intense sensory aversion, fear of eating-related consequences, or limited interest in food may be more prominent than body dissatisfaction. In children, loss of growth velocity or difficulty progressing with eating may be more revealing than an overt complaint. AAP

Physical and developmental signs

Possible physical signs include dizziness, fainting, fatigue, feeling cold, gastrointestinal symptoms, dehydration, weakness, menstrual disruption where applicable, delayed pubertal development, dental changes, or unexplained changes in weight and growth. Electrolyte disturbances, heart-rate abnormalities, and bone-health effects may occur without dramatic external changes. Rapid weight loss, prolonged undernutrition, and persistent vomiting or other compensatory behaviors deserve medical evaluation even when the person is within a conventional population weight range. SAHM medical management paper

A person can also have nutritional deficiencies or severe psychosocial impairment without losing visible weight. For adolescents, comparison with their own previous growth trajectory is often more clinically relevant than a single measurement. Professionals interpret anthropometric data together with developmental stage and physical examination, and avoid relying on BMI alone to judge whether someone needs care.

What Causes Eating Disorders? Risk Factors and Maintaining Mechanisms

There is no single established cause of eating disorders. Genetic vulnerability, temperament and psychological processes, developmental circumstances, social and cultural environments, and biological changes associated with undernutrition can interact. An association with a risk factor does not mean it caused the disorder in a particular person. The American Psychiatric Association and NIMH describe these conditions as multifactorial illnesses requiring individualized formulation and care. APA guideline NIMH

Genetics, development, and temperament

Family and twin research supports a heritable component in several eating disorders, although inherited vulnerability does not determine an individual's outcome. Traits such as anxiety sensitivity, obsessive or perfectionistic tendencies, and difficulty tolerating uncertainty may contribute in some people. Puberty, changes in autonomy and peer relationships, and developmental shifts in appetite, identity, and self-evaluation can alter the context in which symptoms begin. Different diagnoses likely involve partially different pathways, and their relative contributions remain active research questions.

Dietary restriction and the symptom cycle

For many people with anorexia, bulimia, or binge-eating presentations, ongoing restriction can increase preoccupation with food and make loss-of-control eating more likely. Binge eating may then be followed by distress, shame, or renewed restraint, creating a self-reinforcing pattern. In restrictive disorders, malnutrition itself can intensify rigidity, anxiety, and concentration problems, making psychological change more difficult until nutrition is supported. Clinical treatments therefore address both behavior and psychological maintenance processes rather than attributing symptoms to willpower. NICE treatment recommendations

Emotion, trauma, and co-occurring conditions

Some individuals describe using eating-related behavior to manage distress, numb overwhelming feelings, establish predictability, or respond to interpersonal stress. Depression, anxiety disorders, obsessive-compulsive symptoms, substance-use problems, trauma histories, and neurodevelopmental differences can coexist with eating disorders. These relationships vary by person; trauma is neither required for diagnosis nor a complete explanation of every case. Assessment should address co-occurring conditions directly while preserving the independent treatment needs of the feeding or eating disorder. NIMH

Culture, social comparison, and stigma

Appearance ideals, weight-related teasing or stigma, sports or occupational pressures, peer norms, and diet-culture messages can contribute to risk or prolong distress. The effects of social media differ across platforms, content, vulnerabilities, and patterns of engagement, and observational correlations should not be described as proof of individual causation. General appearance-comparison mechanisms are covered separately in our Social Media and Body Image guide, while this article focuses on clinical eating disorders.

Who Can Develop an Eating Disorder?

Eating disorders occur in children, adolescents, adults, and older people, including men and boys and people with diverse gender identities. Assumptions that an affected person must be thin, female, young, or visibly distressed can delay recognition. Male patients may present with different or less readily recognized concerns, including muscularity-focused behaviors, while people in larger bodies may have restrictive symptoms overlooked. The same symptoms may have different nutritional consequences depending on age, growth needs, pregnancy, illness, or activity demands. NIMH SAHM

Autistic people and people with sensory processing differences may experience food selectivity, routine dependence, gastrointestinal difficulties, or ARFID, but autism alone does not imply an eating disorder. Athletes may face additional risks through intense training environments or low energy availability. People with type 1 diabetes need especially careful evaluation when eating-related distress affects essential medical management. Such intersections warrant appropriate specialists and should not be reduced to a single explanation.

How Are Eating Disorders Diagnosed?

Diagnosis is a clinical process involving a detailed history of food intake, binge episodes, perceived loss of control, restriction, compensatory behavior, fears, beliefs about food and body, emotional distress, physical symptoms, and effects on daily life. Clinicians consider onset and duration, age, weight and growth history, medical conditions, medications, social circumstances, and cultural context. A medical examination may include cardiovascular measures, review of hydration and nutritional status, blood tests, and an electrocardiogram where indicated. Psychological and medical evaluation are complementary rather than interchangeable. APA guideline AAP report

Screening questionnaires: useful starting points with limits

Tools such as SCOFF or the Eating Disorder Examination Questionnaire can identify patterns worth exploring and can support symptom monitoring when used appropriately. They do not independently determine a diagnosis, measure medical stability, or replace a clinical interview. A negative screen does not establish safety, especially when someone has atypical anorexia, ARFID, emerging symptoms, or a presentation outside the instrument's main validation population. NICE explicitly advises against using screening tools as the sole basis for determining whether a person has an eating disorder. NICE NG69, assessment

Differential diagnosis: what else can resemble an eating disorder?

Loss of appetite may accompany physical illness, medication effects, depression, or digestive disease. Food avoidance may reflect swallowing disorders, food allergy, gastrointestinal pain, fear of choking, sensory sensitivities, or ARFID. Repeated regurgitation calls for assessment of reflux and other gastrointestinal causes. Weight change alone does not distinguish a feeding disorder from an endocrine or metabolic condition. Clinicians assess body-shape or weight concerns, sensory and fear pathways, loss-of-control eating, medical findings, and functional impairment to determine whether a recognized eating disorder, another condition, or more than one problem is present.

Fear of swallowing or choking is an important differential when someone avoids eating; a distinct discussion is available in Choking Phobia: Fear of Choking, Eating Avoidance, and Differential Diagnosis. Eating disorder specialists and appropriate medical professionals may need to work together, particularly where nutrition or swallowing safety is uncertain.

Medical Risks: Why Body Size Is Not a Safety Test

Inadequate intake can affect heart rate, blood pressure, electrolyte balance, temperature regulation, gastrointestinal function, bone health, fertility-related physiology, and brain function. Purging behaviors can create abrupt fluid and electrolyte disturbances and cardiac danger. Binge-eating disorder may coexist with cardiometabolic or gastrointestinal problems, although these outcomes must not be assumed from the diagnosis or body size alone. Adolescents face additional risks to growth and pubertal development. NIMH SAHM

A particularly important principle is that medically serious restriction can occur at many weights. Rate and magnitude of weight change, bradycardia or other vital-sign abnormalities, dehydration, weakness, laboratory abnormalities, and behavior can be more revealing than appearance. Assessment of medical instability takes priority over assumptions based on BMI. Patients with prolonged undernutrition may need supervised nutritional restoration because changing nutritional intake can carry specific metabolic risks in severely malnourished individuals. Those risks are evaluated and managed by clinicians, not through self-directed refeeding protocols. SAHM

When to seek emergency care

Seek emergency medical attention for collapse or fainting with concerning symptoms, chest pain, severe weakness or confusion, seizures, suspected serious dehydration, repeated vomiting with significant illness, or signs of dangerous heart problems. If there is imminent risk of self-harm or suicide, use local emergency services immediately. In the United States, call 911 for a life-threatening emergency; call or text 988 for immediate suicide or emotional crisis support. A person can require urgent evaluation even while communicating normally or appearing outwardly well. NIMH emergency guidance

Evidence-Based Eating Disorder Treatment

Treatment is individualized by diagnosis, age, medical stability, comorbidity, access to care, and the person's circumstances. Most plans combine eating-disorder-focused psychotherapy, appropriate nutritional rehabilitation, medical monitoring, and practical support from caregivers or loved ones. Severe medical instability may require hospitalization before or during psychiatric treatment. The clinician's goal is sustained improvement in eating behavior, physical and nutritional health, cognitive and emotional functioning, relationships, and quality of life, with ongoing attention to relapse risk. APA 2023 guideline

Psychotherapy for anorexia nervosa

For adults with anorexia nervosa, NICE recommends consideration of eating-disorder-focused cognitive behavioral therapy (CBT-ED), MANTRA, or specialist supportive clinical management, while medical and nutritional restoration are integrated into treatment. For children and adolescents, eating-disorder-focused family therapy is a leading first-line approach when appropriate. Family-focused interventions support caregivers in helping restore adequate eating and gradually return age-appropriate independence. Evidence from recent systematic reviews is encouraging but varies across designs, settings, and outcome measures. NICE recommendations Wergeland et al. systematic review and meta-analysis

Treatment for bulimia nervosa and binge-eating disorder

For adults with bulimia nervosa, supported approaches include eating-disorder-focused guided self-help and individual CBT-ED, with individualized medical assessment of compensatory behaviors and associated risks. For adults with binge-eating disorder, guided self-help and eating-disorder-focused CBT are central interventions; treatment targets episodes, loss of control, distress, rigid restraint, and maintaining thoughts and emotions. Family approaches may be appropriate for younger patients. Treatment should be matched to diagnosis, clinical severity, developmental stage, and preference. NICE NG69

Treatment for ARFID, OSFED, pica, and rumination disorder

ARFID care may involve specialized nutritional support, medical and developmental evaluation, structured behavioral work addressing the individual sensory, fear, or low-interest pathway, and collaborative involvement of family when appropriate. Some interventions use carefully supervised exposure and food-related skill development; evidence remains less extensive than for established treatments of anorexia or bulimia. OSFED is often treated according to the evidence-based approach for the diagnosis it most closely resembles. Pica and rumination require careful medical and developmental assessment, followed by targeted behavioral and environmental interventions appropriate to the identified drivers and risks. NICE NG69 AAP

Medications: diagnosis-specific roles and limitations

Medication can help selected patients, but it is not a substitute for medical and nutritional care or disorder-focused psychotherapy. In the United States, fluoxetine has an approved role in bulimia nervosa, and lisdexamfetamine has an approved indication for moderate-to-severe binge-eating disorder in adults; prescribing decisions require assessment of risks, contraindications, psychiatric comorbidity, and clinical history. No medication is FDA-approved specifically to treat anorexia nervosa or ARFID. Treatment evidence for one eating disorder, one age group, or one medication must not be generalized to all eating disorders. NIMH treatment overview APA guideline

Levels of care and the multidisciplinary team

Outpatient care can be effective for medically stable patients with appropriate support. Intensive outpatient, day, residential, or inpatient services may be needed when symptoms, functional impairment, or medical complications exceed what can safely be managed in a lower level of care. Specialists may include primary-care or adolescent-medicine clinicians, psychiatrists, psychologists, appropriately trained therapists, registered dietitians, nurses, and other medical professionals. Hospital admission is guided by the individual's condition, not a single score or universal body-weight cutoff. SAHM NICE

Eating Disorder Recovery: What Improvement Looks Like

Recovery usually involves more than stopping one visible behavior. Progress can include improved nutritional stability, reduced fear and rigidity, fewer binge or compensatory episodes, improved emotional flexibility, stronger social participation, restoration of age-appropriate growth or physical functioning, and greater freedom from food-related preoccupation. The pace differs across diagnoses and individuals. Some people recover steadily, while others need treatment adjustments, additional levels of support, or renewed care during periods of stress. Relapse prevention and follow-up are part of effective treatment rather than evidence that the person has failed.

Treatment outcomes are measured differently across studies: reduction of symptoms, remission of diagnostic criteria, weight restoration where medically indicated, physical stability, function, and patient-reported well-being may not improve at identical rates. The evidence base is strongest for particular interventions in specific diagnostic groups; outcomes in diverse gender groups, older adults, medically complex patients, and less common eating disorders are often less extensively studied. A careful care plan monitors what matters clinically rather than treating one number as complete recovery. APA guideline

How to Get Help for Yourself or Someone Else

If eating patterns are causing distress, shame, medical symptoms, nutritional concerns, or interference with normal life, arrange an appointment with a health professional familiar with eating disorders. Describe the behaviors and changes directly, including restriction, binge episodes, compensatory behavior, fear around food, dizziness, and changes in growth or weight, even if they seem embarrassing. A primary-care clinician can begin medical evaluation and refer to an eating disorder specialist; children and adolescents should have age-appropriate medical assessment. Seek urgent rather than routine care when there are acute physical warning signs.

When supporting another person, focus on specific observed changes and concern for their health and well-being. Invite a conversation without criticism about weight, appearance, morality, or willpower. Offer practical help arranging an appointment and, where welcome, accompanying them. Families can participate constructively in treatment, especially for adolescents, while respecting the person's age, autonomy, and clinical needs. Because an affected person may feel conflicted about change, repeated calm support and coordinated professional care are often more useful than confrontation. NIMH NICE

Frequently Asked Questions

Can you have an eating disorder at a normal or higher body weight?

Yes. Bulimia nervosa, binge-eating disorder, ARFID, OSFED, and atypical anorexia can occur without an underweight appearance. Clinicians assess symptoms, impairment, medical status, and weight trajectory. Medical risk may be substantial even when BMI is not low. SAHM

What is the difference between an eating disorder and disordered eating?

Disordered eating refers broadly to problematic behaviors or attitudes. A diagnosable eating disorder requires a specific pattern and clinically meaningful consequences evaluated against established criteria. A person with subthreshold symptoms may still need timely help; not meeting one definition is not a medical safety finding.

Are eating disorders only about wanting to lose weight?

No. Weight and shape concerns are central in some disorders, but ARFID can arise from sensory sensitivity, low interest in food, or fear of aversive consequences. Pica and rumination have different defining patterns. Accurate diagnosis depends on understanding what drives the behavior.

Is binge eating the same as overeating?

No. A clinical binge episode has defined features that include a sense of loss of control and, in BED, associated distress and a recurrent pattern. Ordinary overeating or eating more than planned does not establish BED, and self-judgment about food quantity is not sufficient for diagnosis.

Is orthorexia an official diagnosis?

Orthorexia is a proposed construct rather than a separate DSM-5-TR or ICD-11 diagnosis. Rigid eating rules can still cause serious distress or harm; the right response is clinical assessment of the behaviors and consequences, including whether an established diagnosis applies. Donini et al.

Can an online screening test tell whether I have an eating disorder?

No. A questionnaire can prompt further evaluation or help track symptoms, but diagnosis and medical-risk assessment require a qualified professional. NICE cautions against making this determination from screening instruments alone. NICE

Which therapy works best?

It depends on the diagnosis, age, and medical circumstances. Family-based approaches have strong guideline support for many adolescents with anorexia; CBT-based approaches have substantial evidence for bulimia and binge-eating disorder; adult anorexia care also includes MANTRA and specialist supportive clinical management. ARFID and less common disorders require tailored interventions with developing evidence. NICE

Can eating disorders be life-threatening even before someone looks ill?

Yes. Dehydration, electrolyte problems, cardiac effects, and severe undernutrition can be medically important before outward appearance makes the risk obvious. Rapid changes or troubling physical signs require prompt assessment. SAHM

Do eating disorders ever fully resolve?

Recovery is possible. Many people make meaningful and sustained improvements with timely, diagnosis-appropriate treatment and continuing support. Outcomes and recovery timelines vary, so long-term monitoring should address both symptom recurrence and physical or psychological well-being.

Where should someone in the United States start?

A primary-care clinician, pediatrician, or eating-disorder specialist can initiate evaluation. Mental-health referrals can also begin through established health systems and insurance networks. For immediate suicidal crisis, call or text 988; for a life-threatening medical emergency, call 911. Clinical assessment is especially important where fainting, chest symptoms, dehydration, or significant nutritional restriction is present. NIMH

Related Articles

Social Media and Body Image: Appearance Comparison, Ideals, and Mental Health — for the broader psychology of appearance comparison and media environments.

Choking Phobia: Fear of Choking, Eating Avoidance, and Differential Diagnosis — for the specific phobia and medical differential relevant to some food avoidance presentations.

References

American Psychiatric Association. (2023). Practice Guideline for the Treatment of Patients With Eating Disorders. Official clinical guideline.

Donini, L. M., Barrada, J. R., Barthels, F., et al. (2022). A consensus document on definition and diagnostic criteria for orthorexia nervosa. Eating and Weight Disorders, 27, 3695–3711. https://doi.org/10.1007/s40519-022-01512-5.

Hornberger, L. L., Lane, M. A., & Committee on Adolescence. (2021). Identification and management of eating disorders in children and adolescents. Pediatrics, 147(1), e2020040279. https://doi.org/10.1542/peds.2020-040279.

National Institute for Health and Care Excellence. (2017; updated). Eating disorders: Recognition and treatment (NG69). Guideline recommendations.

National Institute of Mental Health. (2024; current online edition). Eating Disorders: What You Need to Know. NIMH resource.

Society for Adolescent Health and Medicine. (2022). Medical management of restrictive eating disorders in adolescents and young adults. Journal of Adolescent Health, 71(5), 648–654. https://doi.org/10.1016/j.jadohealth.2022.08.006.

Wergeland, G. J., Ghaderi, A., Fjermestad, K., et al. (2025). Family therapy and cognitive behavior therapy for eating disorders in children and adolescents in routine clinical care: A systematic review and meta-analysis. European Child & Adolescent Psychiatry, 34, 883–902. https://doi.org/10.1007/s00787-024-02544-1.