Medical Complications of
Anorexia Nervosa and
JAMES E. MITCHELL
Despite a growing literature outlining the medical complications of anorexia nervosa and bulimia nervosa, patients, families, and providers too often are so focused on the psychiatric aspects of the illness that they overlook the physical damage that these conditions can cause. In this chapter, the medical complications of eating disorders are reviewed. (Physiological abnormalities are described in Chapter 48.) It is important to emphasize that awareness of these potentially tragic consequences is the responsibility of all health professionals caring for these vulnerable patients, and that the management of these complications is an essential aspect of the overall management of eating disorders.
Decreased oral intake in restricting anorectic patients and purging behaviors in bulimic patients can result in severe disruptions of fluid homeostasis and potentially life-threatening electrolyte abnormalities. The most frequent serious electrolyte disturbance is hypokalemia, which usually occurs in patients with potassium loss due to self-induced vomiting or diuretic and laxative abuse. Simultaneous loss of fluid and stomach acid often results in an accompanying hypochloremic contraction alkalosis.
Hypokalemia may result in cardiac arrhythmias, one of the major causes of death in patients with eating disorders, and may also contribute to intestinal dysmotility and skeletal muscle myopathy. It is now recognized that chronic hypokalemia can cause nephropathy, with elevated serum creatinine levels, and eventually result in chronic renal failure severe enough to require dialysis.
A number of other electrolyte abnormalities occur less frequently. Hypomagnesemia is not uncommon in anorectic patients and may be associated with hypocalcemia or