Anorexia nervosa produces a wide range of symptoms that go far beyond weight loss. The condition affects the body, mind, and behavior simultaneously, and many of its signs are easy to miss, especially in people who don’t look underweight. Understanding the full picture helps you recognize what’s happening in yourself or someone you care about.
The Core Psychological Symptoms
At its center, anorexia is driven by three interconnected psychological patterns. The first is an intense fear of gaining weight or becoming fat, even when a person is already underweight. This fear doesn’t ease as weight drops. It typically intensifies.
The second is a distorted experience of body size and shape. People with anorexia genuinely perceive their bodies as larger than they are. This isn’t vanity or exaggeration. Research shows that anorexia shares features with body dysmorphic disorder, including a delusional quality where the person has little insight into how distorted their beliefs have become. In anorexia specifically, this delusionality is tied to shape concerns and a relentless drive for thinness.
The third is placing extreme importance on weight and body shape when evaluating self-worth, while simultaneously failing to recognize how serious the weight loss has become. A person deep in anorexia may genuinely not see danger in their condition, even when others around them are alarmed.
Behavioral Warning Signs
The behavioral symptoms are often the first things other people notice. These include counting calories obsessively, cutting out entire food groups, skipping meals, and eating only tiny portions. Food rituals are common: chewing each bite far longer than necessary, rearranging food on a plate, cutting it into very small pieces, or eating in secret.
Exercise habits often shift dramatically. A person may begin exercising compulsively, sometimes for hours, and become anxious or distressed if they can’t complete a workout. Social withdrawal is another hallmark. People with anorexia frequently pull away from friends and avoid situations involving food, like dinners out or family gatherings. Part of this is practical avoidance of eating, but it’s also driven by fear of judgment.
Body checking is another pattern to watch for. This means repeatedly weighing yourself, measuring body parts, pinching skin to assess fat, or spending long periods examining your body in mirrors. Some people do the opposite, avoiding mirrors and scales entirely, but the preoccupation with body size remains constant either way.
Physical Symptoms of Starvation
As the body is deprived of adequate nutrition, it begins to shut down non-essential functions and conserve energy. Resting metabolic rate can drop by as much as 20%, which is the body’s attempt to survive on fewer calories. This slowing produces a cascade of visible and internal changes.
Common physical signs include:
- Feeling cold all the time, because the body can no longer regulate temperature well
- Soft, downy hair (lanugo) growing on the arms, face, and torso, which is the body’s attempt to insulate itself
- Dry, yellowish skin and brittle nails
- Hair thinning or loss on the scalp
- Dizziness and fainting, caused by low blood pressure and dehydration
- Severe constipation from slowed digestion
- Loss of menstrual periods in females not on hormonal contraception
- Fatigue and muscle weakness as the body breaks down its own muscle for fuel
Dangerous Cardiovascular and Electrolyte Effects
The most life-threatening physical symptoms involve the heart and the body’s electrolyte balance. Anorexia causes irregular heart rhythms (arrhythmias) and low blood pressure. These arrhythmias can be fatal and are one of the leading causes of death in anorexia.
Prolonged starvation depletes essential minerals like phosphorus, potassium, and magnesium. Low potassium causes muscle cramps, extreme fatigue, and in severe cases, respiratory failure and dangerous heart rhythms. Low magnesium affects virtually every organ, triggering tremors, muscle spasms, nausea, and seizures. Phosphorus deficiency, the most common electrolyte problem in severe anorexia, impairs cellular processes throughout the body and can lead to muscle weakness, trouble breathing, swallowing problems, and heart failure.
These electrolyte shifts become especially dangerous during recovery. When a severely malnourished person begins eating again, the sudden metabolic demand can cause a life-threatening condition called refeeding syndrome, where remaining electrolytes rush from the blood into cells, leaving critically low levels in the bloodstream.
Two Subtypes With Different Patterns
Anorexia is classified into two subtypes, and the symptoms look somewhat different in each. The restricting type involves weight loss through fasting, severely limiting food intake, and excessive exercise, without episodes of binging or purging. This is the presentation most people picture when they think of anorexia.
The binge-eating and purging type involves episodes of eating larger amounts of food followed by compensatory behaviors like self-induced vomiting or misuse of laxatives and diuretics. This subtype carries additional risks. Research consistently finds higher rates of suicidality, impulsivity, substance use, and co-occurring psychiatric conditions in the binge-purging type compared to the restricting type. People with this subtype may also develop swollen salivary glands, dental erosion from repeated vomiting, and more severe electrolyte disturbances.
Symptoms in Men and Atypical Presentations
Anorexia is widely perceived as a condition affecting young women, but it occurs across all genders, ages, and body types. In males, the disorder is significantly underreported. Boys and men are less likely to seek help because of societal assumptions that eating disorders are a female problem. The symptoms may also look different. Men with anorexia are more likely to focus on muscularity and leanness rather than thinness alone, which means standard diagnostic criteria sometimes fail to catch their disordered patterns. Transgender men show particularly elevated rates of eating disorder symptoms.
Atypical anorexia is another commonly missed presentation. A person with atypical anorexia has all the same psychological and behavioral symptoms: the fear of weight gain, the distorted body image, the dangerous restriction. The difference is that they started at a higher weight, so even after significant weight loss, they may appear average-sized or above. This makes it easy for others, including healthcare providers, to overlook the problem. The medical consequences, including heart complications and electrolyte imbalances, are just as serious regardless of what the person currently weighs.
How Severity Is Measured
Clinical severity in adults is categorized by BMI. Mild anorexia corresponds to a BMI of 17 or above, moderate falls between 16 and 16.99, severe between 15 and 15.99, and extreme is below 15. For children and adolescents, BMI percentiles are used instead. These categories can be adjusted upward based on how impaired the person’s daily functioning is and how much supervision they need, meaning someone with a BMI of 17 can still be classified as more severe if their symptoms are significantly affecting their life.
It’s worth noting that these BMI thresholds apply only to typical anorexia. A person with atypical anorexia may have a BMI well above 17 and still be medically compromised from rapid, severe caloric restriction. The number on the scale is only one piece of the picture.