Eating disorders are serious mental illnesses in which distressing thoughts and behaviours around food, eating, weight, or body shape take hold and interfere with a person's health and life. They are not about vanity or willpower, they carry real medical risk, and they can affect people of any gender, age, culture, and body size. Crucially, they are treatable, and recovery is possible.
This overview does three things. First, it sets out plainly what an eating disorder is and what it is not. Second, it introduces the main recognised types as a set of distinct conditions rather than a single problem. Third, it corrects the two myths that do the most damage: that eating disorders are a choice, and that they only affect young, visibly underweight women. The other pages in this section then go deeper on the warning signs, the causes, treatment, coping and support, and what the research shows.
What an eating disorder actually is
An eating disorder is a mental illness in which a person's thoughts, feelings, and behaviours around eating become disordered in a way that harms their physical health, their emotional wellbeing, or their ability to live their life. What sets it apart from ordinary worries about food or appearance, which are extremely common, is the grip it takes and the harm it causes. The concern becomes consuming, the behaviours become hard to control or stop, and self-worth often becomes tightly, painfully bound up with eating, weight, or body shape.
It helps to be clear about what an eating disorder is not. It is not a diet that went a bit far. It is not attention-seeking, a passing phase, or a sign that someone is weak or shallow. And it is not something a person can simply decide to stop, any more than depression or anxiety can be switched off by choice. Eating disorders are recognised as psychiatric conditions in the major diagnostic systems, including the DSM-5-TR, precisely because they involve genuine, involuntary changes in how the mind works, not a lack of effort or good sense.
They are also medically serious. Disordered eating can affect nearly every system in the body, and some eating disorders are associated with among the highest risk to physical health of any mental illness. That seriousness is not a reason to panic, but it is a reason to treat these conditions with the same respect and urgency as any other significant illness, and to seek help rather than wait.
Two myths to clear away first
Before describing the types, it is worth confronting the two beliefs that most often stop people from recognising an eating disorder or reaching out. Both are common, both feel intuitive, and both are wrong.
Eating disorders are a choice, a diet, or a bid for control that someone could stop if they wanted to.
They are serious mental illnesses with biological, psychological, and social roots. The behaviours are driven by a disorder, not chosen freely, and just eating normally or just stopping is not something willpower alone can deliver. This is why compassion and proper treatment matter far more than blame.
Eating disorders only affect young, thin, white women.
They affect people of every gender, age, ethnicity, and body size. Men and boys, older adults, and people in larger bodies all develop eating disorders, and are more likely to be overlooked because of this very stereotype. A person's size is not a measure of how ill they are.
The main types of eating disorder
Eating disorders are not one condition but a family of related ones. The types below are the most widely recognised. They can overlap, a person's diagnosis can change over time, and someone can be seriously unwell without fitting any category neatly. The point of naming the types is not to label people but to show the range, and to make clear that no single picture captures them all.
Anorexia nervosa
Marked by severe restriction of what is eaten, an intense fear of weight gain, and a distorted experience of one's own body. It carries serious medical risk and among the highest mortality of any mental illness. It is not defined by appearance alone, and a person does not have to look a certain way to be dangerously unwell.
Bulimia nervosa
A cycle of episodes of feeling out of control with eating, followed by behaviours intended to compensate or undo them. Distress about weight and shape is central. People with bulimia are often not underweight, which is one reason the illness is frequently hidden and missed.
Binge eating disorder
Recurrent episodes of eating that feel out of control and are accompanied by real distress, shame, or guilt, without the regular compensating behaviours seen in bulimia. It is the most common eating disorder, affects all body sizes, and is a genuine illness, not a lack of discipline.
OSFED and ARFID
OSFED (other specified feeding or eating disorder) covers serious eating disorders that do not fit the categories above, and is very common. ARFID (avoidant or restrictive food intake disorder) involves avoiding or restricting food for reasons unrelated to weight or shape, such as sensory difficulty or fear of a bad experience. Both are real and treatable.
One thread runs through all of these types and is worth holding on to: none of them can be judged by appearance. Binge eating disorder and bulimia often occur in people who are not underweight, OSFED covers serious illness that does not fit the tidy categories, and even anorexia is not defined by looking a certain way. Someone can be dangerously unwell while appearing physically well, and someone in a larger body can be just as ill as anyone else. The differences between the types matter for treatment, but the shared truth matters more for recognition: each is a real illness, and each deserves to be taken seriously.
The symptoms page describes the warning signs across these conditions in general, non-diagnostic terms, and the causes page explains why they develop. What every type shares is that it is a genuine illness, it deserves care rather than judgement, and it can be treated.
How serious, and how common
A few general points give a sense of scale. These are drawn from population research and clinical guidance and are broad rather than precise, but the shape of the picture is consistent and important.
The most important takeaway is the balance of these facts. Eating disorders are serious, and they should never be minimised. But they are also treatable, and the earlier someone reaches help the better the outlook tends to be. Seriousness and hope are not in tension here: both are true, and both are reasons to act rather than wait.
Where to go next
This overview is the map. The other pages fill in the detail: the warning signs, the causes, the treatment that helps, ways of coping and supporting a loved one, and what the research shows.
Sources
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). 2022.
- National Institute for Health and Care Excellence. Eating disorders: recognition and treatment (NG69). 2017.
- Beat. Types of eating disorder and general information. Accessed 2026.
This page is educational and is not medical advice. It does not diagnose any condition. Eating disorders can only be assessed and diagnosed by a qualified healthcare professional. If you are worried about yourself or someone else, please speak with a doctor. If you are in crisis or in immediate danger, contact your local emergency services now. For eating disorder support you can also contact a helpline such as Beat in the UK (call 0808 801 0677) or a national eating disorders or mental health helpline in your country; if you are unsure where to turn, your local emergency services or a general crisis line can help.