hormonal and metabolic disorders
Syndrome of Inappropriate Secretion of Antidiuretic Hormone (SIADH)
Diagnosis of SIADH
Blood and urine tests Doctors suspect SIADH in people with hyponatremia that cannot be explained by other factors, such as pain, stress, strenuous exercise, a high blood sugar level, and certain disorders of the heart, thyroid gland, kidneys, or adrenal glands that can decrease blood volume and appropriately stimulate the release ofvasopressinfrom the pituitary. Blood and urine tests are done to measure the sodium and potassium levels and to determine how concentrated the blood and urine are (osmolality). Doctors also rule out other possible causes of excessvasopressin(such as pain, stress, medications, or cancer). Once SIADH is diagnosed, doctors try to identify What Causes SIADH? and address it so the sodium level slowly returns to normal. 