It may result from fasting, famine, anorexia nervosa, catastrophic disease of the GI tract, stroke, or coma. The basic metabolic response to starvation is conservation of energy and body tissues. However, the body will mobilize its own tissues as a source of energy, which results in the destruction of visceral organs and muscle and in extreme shrinkage of adipose tissue. Total starvation is fatal in 8 to 12 wk. Loss of organ weight is greatest in the liver and intestine, moderate in the heart and kidneys, and least in the nervous system.
Emaciation is most obvious in areas where prominent fat depots normally exist.
Muscle mass shrinks and bones protrude. The skin becomes thin, dry, inelastic, pale, and cold. The hair is dry and sparse and falls out easily. Most body systems are affected. Achlorhydria and diarrhea are common.