significant loss of total body weight is a serious, chronic illness. Substantial, unintentional weight loss is a symptom of acute or chronic illness, especially if other evidence is present.
Weight loss, for example, accompanied by insatiable thirst and hunger and fatigue may indicate diabetes mellitus, a chronic disease characterized by an abnormal accumulation of carbohydrates in the bloodstream due to insufficient production of insulin, a hormone produced in the pancreas that, when secreted into the bloodstream, permits cellular metabolism and utilization of glucose.
Poor management of insulin-dependent diabetes mellitus (IDDM), also known as diabetes mellitus type I, leads to an excessive amount of glucose and an insufficient amount of insulin in the bloodstream. This triggers the release of triglycerides from adipose tissue and catabolism of amino acids in muscle tissue. This results in a loss of both fat and lean mass, predisposing a significant reduction in total body weight.