The metabolic syndrome of chronic critical illness (CCI) consists of multisystem organ dysfunction resulting from the initial acute injury and chronic immune-neuroendocrine axis activation, adult kwashiorkor-like malnutrition, and prolonged immobilization with suppression of the PTH-vitamin D axis and hyper-resorptive metabolic bone disease. CCI patients can also present unique challenges in the management of diabetes mellitus, thyroid and adrenal diseases, electrolyte abnormalities and hypogonadism.