Anorexia nervosa is a mental illness and eating disorder, characterized by an obsession with weight, a distorted self-image, and a severe restriction of food. How does this dangerous condition affect physical and mental well-being over time?

For most patients, anorexia usually begins with a restrictive diet which can cause a notable loss of weight and muscle mass. The diet may transition into obsessive calorie counting, skipped meals, overexercising, misuse of laxatives, etc. As a result, physical manifestations may occur due to the body not receiving enough nutrients. Fatigue, dry skin, lightheadedness, hair loss and an abnormally low body temperature are some of the common signs.

The behavior of the anorexic also tends to change. Some may (openly or privately) display a fear of becoming fat and a preoccupation with weight and body measurements. They are also more prone to lying (about whether they ate and how much they ate), social isolation (if they fear intervention from family and friends), and addiction (developing a drug habit to cope with starvation).

Hormone production is disrupted, causing a reduction in thyroid hormones and an increase in stress hormones. For adolescent anorexics, reduced growth hormones may result in retarded growth. Among female patients, menstruation is affected by becoming irregular or disappearing altogether.

Studies show patients gradually end up in a state of delusion and denial. "Refusal to maintain body weight at or above a minimally normal weight for age and height," and "denial of the seriousness of the current low body weight," are named as some of the physiological consequences of anorexia in one case report.

"Medical complications resulting from semi-starvation and overexercising affect virtually every organ system," the authors add. Liver damage is considered a frequent consequence, given how anorexia can alter liver enzymes. Cardiovascular problems such as poor blood circulation, irregular heartbeats, low blood pressure, and heart failure are also likely to arise. Research shows around 90% of women with anorexia experience osteopenia while 40% have osteoporosis, increasing their susceptibility to fracture.

In addition, mental health is severely affected, especially if patients lack a support system in the long run. Studies show depression and anxiety are aggravated among people with eating disorders, often leading to isolation and self-harm. Anorexia is said to have one of the highest mortality rates of all mental illnesses. Death may occur due to suicide or physical health complications.

Anorexic women who are trying to conceive may experience a loss of fertility and an increased risk of miscarriage. Sometimes, the infant may also be affected by birth defects. "In biological terms, it is very reasonable that reproductive function is shut down in response to a depleted nutrient supply," states one study

Overall, the constant cycle of malnutrition and weight loss can have devastating consequences on the functioning of the body and mind. Though a few of these consequences may be irreversible, many patients have been able to completely recover and return to a healthy diet and BMI. "The real focus has to be on weight restoration if you want to reverse outcomes," explains Dr. Rebecka Peebles, a specialist in adolescent medicine at the Lucile Packard Children’s Hospital. "That’s the most essential part of treatment. You can’t wait around for it to happen. It really is an essential first step in treatment and recovery."