A condition that results in the inability to produce dilute urine and imbalance of fluids and electrolytes in the body, par- ticularly lowering blood sodium. Symptoms include nausea, vomiting, muscle cramps, confusion, and convulsions. This syndrome may occur with oat-cell lung cancer, pancreatic cancer, prostate cancer, and Hodgkin’s disease, among other disorders. Also known as syndrome of inappropriate ADH secretion or SIADH.