Both anemia and leukopenia are commonly present, and cholesterol and carotene levels may be elevated. Levels of various hormones are abnormal, suggesting hypothalamic dysfunction. Resting plasma cortisol levels are elevated, and the metabolic clearance of cortisol is decreased. These hormonal findings are caused by starvation and are also found in other syndromes characterized by malnutrition and significant weight loss. Among the more serious medical complications seen in anorexia nervosa are those that affect the cardiovascular system.
Electrocardiography shows a typical low-voltage pattern with bradycardia.
However, arrhythmias, including ventricular arrhythmias, may be caused by both the starvation and the hypokalemia and are implicated in the sudden deaths that occasionally occur in low-weight anorectics. Renal complications may occur in the context of long-term dehydration accompanied by hypokalemia. This combination may cause irreversible damage to renal tubules. Renal calculi have also been reported to occur as a consequence of the dehydration. The differential diagnosis of anorexia nervosa is usually straightforward because the presentation, history, and physical findings are typical of the condition.