Wikipedia Deep Dive

Anorexia nervosa

12 min read

Here is a disease that kills more people than almost any other mental illness—second only to opioid overdose—yet we routinely misunderstand what it actually is. Anorexia nervosa is not vanity. It is not a diet gone too far. It is not something that happens only to teenage girls in wealthy suburbs who read too many fashion magazines.

It is a psychiatric disorder that rewires how a person sees their own body.

The Mirror Lies

Imagine looking in a mirror and seeing something fundamentally different from what everyone else sees. Not in a vague, "I feel fat today" sense, but in a profound, perception-altering way. A person with anorexia nervosa might genuinely fear they cannot fit through a doorway—despite being dangerously underweight, despite having a body significantly smaller than someone of normal weight who would actually struggle with that same narrow space.

This is called body dysmorphia, and it sits at the heart of anorexia. The brain constructs a mental image of the body that bears little resemblance to physical reality. It's not that the person is lying or exaggerating. They genuinely perceive themselves as larger than they are.

The technical term for this is "altered body schema"—a distorted, unconscious perception of one's body size and shape that influences every physical activity. Walking through a room. Sitting in a chair. Moving through the world. All of it filtered through a funhouse mirror that only the person with anorexia can see.

When the Body Stops Talking to the Brain

Your body constantly sends signals to your brain. Hunger. Fullness. Temperature. Pain. This ongoing conversation between body and mind is called interoception, and it's essential for staying alive. You eat when you're hungry. You stop when you're full. You pull your hand away from a hot stove.

In anorexia, this conversation breaks down.

People with the disorder often report strange, indistinct feelings of fullness that arrive too early and too intensely. A few bites of food trigger sensations that a healthy person might experience after a large meal. The signals are scrambled. The calibration is off. And so the person stops eating—not out of willpower or discipline, but because their body is telling them, incorrectly, that they're already full.

This miscommunication extends to emotions as well. Many people with anorexia experience something called alexithymia—difficulty identifying and describing their own feelings. They struggle to distinguish between emotions and bodily sensations. Am I anxious or am I hungry? Am I sad or am I full? The categories blur together, and food becomes tangled up with feelings in complicated, destructive ways.

The Paradox of Control

Anorexia often emerges during adolescence or young adulthood, times of profound change and uncertainty. The developing brain, the shifting body, the upheaval of identity—all of it creates fertile ground for a disorder that centers on control.

Because that's often what anorexia is really about. Not thinness, exactly, but mastery. The ability to resist hunger becomes proof of discipline. The shrinking body becomes evidence of willpower. In a world that feels chaotic and overwhelming, controlling food intake provides an illusion of stability.

Researchers have found that anorexia commonly follows major life changes or stressful events. A move. A breakup. A trauma. Sexual abuse and problematic family relationships appear frequently in case histories—particularly overprotective parents who show excessive possessiveness over their children. The eating disorder becomes a way of asserting autonomy when other forms of control feel impossible.

But the control is always an illusion. The disorder eventually controls the person, not the other way around.

A Disease of Behaviors

The signs of anorexia extend far beyond simply not eating. The disorder manifests in an elaborate constellation of behaviors, each one serving the same obsessive goal.

Food rituals become paramount. Cutting food into tiny pieces. Measuring portions with precision. Refusing to eat around others. Hiding food or secretly discarding it. Some people develop elaborate cooking practices—preparing beautiful, elaborate meals for others that they themselves will not touch, using the activity as both a distraction and a way to be near food without consuming it.

Purging takes many forms. Self-induced vomiting is the most recognized, but excessive exercise, laxative abuse, diet pills, and diuretics all serve the same purpose: preventing weight gain, relieving the physical discomfort of fullness, or atoning for feelings of guilt and impurity that accompany eating. Not everyone with anorexia purges—some focus exclusively on restriction—but the behavior is common enough to be defining.

There's a physical marker called Russell's Sign: scratch marks on the back of the hand from inducing vomiting. Teeth erode from stomach acid. Fine, soft hair called lanugo grows across the face and body—the body's desperate attempt to insulate itself when it no longer has enough fat to stay warm.

And through it all, compulsive weighing. Constant body checking. An obsession with calories that consumes hours of every day.

What Happens to the Body

Self-imposed starvation damages every major organ system. The heart weakens and can develop dangerous rhythm abnormalities. Bones lose density, leading to osteoporosis even in young people. Menstrual periods stop. Fertility disappears. Hair thins and falls out. Skin becomes dry and may turn orange from carotenosis, a harmless but visible sign of malnutrition.

Low potassium—a condition called hypokalemia—causes muscle damage, fatigue, constipation, and in severe cases, paralysis. Body temperature drops. Blood pressure falls. The brain itself changes, deprived of the nutrients it needs to function properly.

In men, testosterone levels plummet. The physical effects are just as severe, though anorexia in men is often diagnosed later because doctors aren't looking for it.

About five percent of people with anorexia die from complications within ten years. That's an extraordinarily high mortality rate for any psychiatric condition. Medical complications are the primary cause of death. Suicide is the secondary cause.

The Genetic Lottery

For a long time, anorexia was blamed entirely on culture—fashion magazines, thin celebrities, unrealistic beauty standards. And culture does play a role. Societies that prize thinness have higher rates of the disease. Athletes in sports where low body weight provides competitive advantage—dance, gymnastics, figure skating, cheerleading, distance running, ski jumping—develop anorexia at elevated rates, a phenomenon sometimes called anorexia athletica.

But culture alone doesn't explain why one person develops anorexia while another, exposed to the same pressures, does not.

Twin studies have revealed a strong genetic component. Identical twins are far more likely to both develop anorexia than fraternal twins. The heritability rate falls somewhere between twenty-eight and fifty-eight percent—substantial by any measure. First-degree relatives of someone with anorexia have roughly twelve times the risk of developing the disorder themselves.

Researchers have identified polymorphisms in genes related to eating behavior, motivation and reward, personality traits, and emotion regulation. The picture is complex—at least forty-three different genes and over a hundred genetic variations appear to play roles. Some of these genes overlap with those implicated in schizophrenia, obsessive-compulsive disorder, anxiety, and depression. There's even a metabolic component: genetic correlations with fat mass, type two diabetes, and leptin (the hormone that signals satiety).

This isn't to say that anorexia is purely biological. It's to say that some people are born more vulnerable to it than others, and that environmental triggers interact with genetic predisposition in ways we're only beginning to understand.

The Crowded Mind

Anorexia rarely arrives alone. The majority of people with the disorder have at least one other psychiatric condition, and many have several.

Depression and anxiety are the most common companions. Depression in particular predicts worse outcomes—harder recovery, higher risk of relapse. Obsessive-compulsive disorder appears frequently, which makes sense given how much anorexia involves ritualistic behaviors and intrusive thoughts. Post-traumatic stress disorder is highly prevalent, and more severe PTSD correlates with more severe eating disorder symptoms.

Here's a statistic that surprised researchers: approximately thirty percent of children and adults with anorexia nervosa may also have autism spectrum disorder. That's dramatically higher than the general population. Some scientists have proposed that autism-related traits—rigid thinking, difficulty with social cognition, sensory sensitivities—constitute part of the underlying cognitive profile that makes a person vulnerable to anorexia.

The relationship between personality disorders and eating disorders remains murky. Borderline personality disorder, other personality disorders, substance abuse, alcoholism, attention deficit hyperactivity disorder, body dysmorphic disorder—all appear at elevated rates. Whether these conditions predispose people to anorexia or whether anorexia itself promotes their development remains unclear. Probably both.

The Difficulty of Knowing You're Sick

One of the cruelest features of anorexia is that it often erases awareness of itself. The technical term is anosognosia: unawareness or denial of the severity of one's condition.

This isn't stubbornness or lying. The same distorted perception that makes a person see their body as larger than it is can also prevent them from recognizing how sick they've become. They genuinely believe they're fine. They may acknowledge the behaviors but not their danger. They may intellectually understand they're underweight but feel viscerally certain they're too fat.

This creates an impossible bind. How do you convince someone to get help for a problem they can't see? How do you treat a disease that hijacks the very mechanism—self-awareness—needed to recognize it?

In the most severe cases, psychiatrists can declare a patient lacks the capacity to make decisions about their own care. Medical proxies then step in, and forced feeding through a nasogastric tube becomes an option. It's a last resort, deeply controversial, and the evidence for its effectiveness remains unclear.

Getting Better

Treatment for anorexia requires addressing multiple dimensions simultaneously: restoring weight, treating the underlying psychological disturbance, and changing maladaptive behaviors. None of these is simple. None of them works quickly.

Weight restoration comes first because the brain cannot function normally during starvation. Many of the cognitive distortions that drive anorexia actually worsen as malnutrition progresses. The rigid thinking, the difficulty with abstract reasoning, the impaired theory of mind—all of these improve, at least somewhat, when the body receives adequate nutrition. You cannot think your way out of a starving brain.

Various therapy approaches show promise. Cognitive behavioral therapy helps patients identify and challenge the distorted thoughts that maintain the disorder. For adolescents, an approach called Maudsley family therapy places parents in charge of feeding their child—taking the decision-making away from the patient entirely until weight is restored and healthier patterns can emerge.

Medications play a supporting role. A daily low dose of olanzapine, an antipsychotic medication, has been shown to increase appetite and assist with weight gain. Psychiatrists often prescribe medications for the anxiety and depression that accompany anorexia, though these treat symptoms rather than the core disorder.

Some patients require hospitalization. Some recover with outpatient treatment. Some have a single episode and never relapse. Others cycle through recovery and relapse for years.

The numbers are sobering. Within the first year after discharge from treatment, relapse rates peak. Approximately thirty-one percent of patients relapse within two years. The good news is that many complications—both physical and psychological—improve or resolve entirely with adequate weight gain and nutritional rehabilitation. The body is remarkably resilient, if given the chance.

Who Gets Anorexia

The stereotype says young white women. The reality is more complicated.

Anorexia does affect women more than men—roughly ten times more commonly, by most estimates. In Western countries, somewhere between 0.3 and 4.3 percent of women will experience anorexia at some point in their lives, compared to 0.2 to 1 percent of men. About 0.4 percent of young women are affected in any given year.

But those numbers almost certainly undercount men, who are less likely to be diagnosed because clinicians aren't looking for the disorder in them. They're also less likely to seek help, partly because of stigma and partly because they may not recognize their symptoms as anorexia.

Whether anorexia has genuinely become more common over the twentieth and twenty-first centuries, or whether we've simply gotten better at recognizing and diagnosing it, remains an open question. The answer is probably both.

In 2013, anorexia directly caused approximately six hundred deaths globally, up from four hundred deaths in 1990. But these numbers capture only deaths directly attributable to the disorder. They don't include deaths from the wide range of other causes—including suicide—that become more likely when someone has an eating disorder.

The Gut Connection

A fascinating and relatively recent area of research explores the relationship between gastrointestinal diseases and eating disorders. People with gastrointestinal problems appear more vulnerable to developing restrictive eating patterns. Celiac disease—an autoimmune reaction to gluten—shows a particular association with anorexia nervosa.

The connection makes intuitive sense. If eating certain foods makes you sick, you develop anxiety around food. You become hypervigilant about what you consume. You worry about contamination, about ingredients, about the safety of every meal. What begins as medically necessary dietary management can, in vulnerable individuals, tip over into something more pathological.

This suggests that anorexia isn't always about body image at all. Sometimes it's about fear. Fear of pain. Fear of illness. Fear of losing control over what happens inside your own body.

The Questions We Can't Yet Answer

After decades of research, the exact cause of anorexia nervosa remains unknown. We know that genetics matter, but we can't predict who will develop the disorder based on their genes. We know that culture matters, but we can't explain why most people exposed to thin-ideal media never become anorexic. We know that trauma and family dynamics matter, but plenty of people with terrible childhoods never develop eating disorders, and plenty of people with loving families do.

What we can say is this: anorexia nervosa is a serious psychiatric illness with biological, psychological, developmental, and sociocultural risk factors. It is not a choice. It is not a phase. It is not about willpower, either having too much of it or too little.

It is a disease of perception—of seeing yourself as something you're not, of feeling full when you're starving, of believing you're in control when you're dying.

And it can be treated. Not easily. Not quickly. Not always successfully. But the brain can learn to see the body accurately again. The conversation between gut and mind can be recalibrated. The mirror can stop lying.

Recovery is possible. That's worth remembering.