Psychogenic polydipsia leading to severe hyponatremia is well documented in the literature. This electrolyte disorder can result in encephalopathy, cerebral edema and epileptic seizures. Another rare effect is rhabdomyolysis with all its well known complications (e.g. renal failure, hyperkalemia and cardiac arrhythmia) and even resulting in compartment syndrome due to severe muscle edema. We present the case of a patient with severe hyponatremia caused by psychogenic polydipsia leading to rhabdomyolysis and compartment syndrome.