Failure to thrive in the elderly.

Failure to thrive in the elderly is a syndrome and not a diagnosis. It encompasses a number of conditions characterized by progressive weight loss and decrease in function. For purposes of diagnosis and treatment, failure to thrive can be divided into nonorganic and organic causes. Nonorganic causes include psychosocial problems and difficulties with physical function. Organic causes include known diseases and, possibly, unknown age-associated changes in nutrition, regulation of inflammation, and anabolic and catabolic hormones.