Anorexia causes the whole body to be undernourished. The intake of nutrients, electrolytes and water is insufficient. This can lead to long-term mental and physical consequences: excessively slow heartbeat, heart and kidney disorders, osteoporosis, hormonal disturbances progressing to infertility, impotence, loss of nerve cells, anaemia, loss of heart muscle and skeletal muscle, depression, isolation and anxiety disorders. Anorexia that starts at an early age can impact development: menarche does not occur and bone growth can be impaired.
As the disease progresses, the body does not function properly. A mild bacterial infection can become lethal. Anorexia nervosa has the highest case-fatality rate of all mental diseases.