Childhood undernutrition belongs to what Chinese medicine calls gan pattern. Undernutrition is due to insufficient intake of food or insufficient absorption of nutrients resulting in inability to maintain proper metabolism, forcing the body to consume its own tissue. Consequently there is no increase in body weight or the body loses weight, growth and development cease, fat deposits gradually diminish and muscles atrophy. This can also lead to complete functional breakdown of the body's systems and lowered immunity. Clinical characteristics include emaciation, irregular intake of food and, if extreme, dry, slack skin, vexation, agitation, listlessness and retarded mental and motor development.