What is SIADH?
SIADH is a disease in which there is commonly an inappropriately high production and therefore high concentration of the hormone vasopressin circulating in the blood resulting in retention of salt (sodium) and water. In healthy individuals vasopressin and the V2 receptor play an important role in the regulation of the body’s salt and water balance. If the salt and water balance is not correctly maintained this can result in symptoms. When sodium levels fall or as is the case in SIADH, the body's water levels rise, causing dilution of sodium, the cells in the body to swell. This swelling can cause many health problems, from mild to severe, seen in hyponatremia. Course of the disease is dependant on the degree and speed with which hyponatremia develops, the underlying cause of SIADH and the success of treatment among other things.