Hello, Thank you for your query. Would you please clarify a few things for me? 1) Is your husband a diabetic, hypertensive? 2) does he have thyroid disease? heart disease? kidney disease. 3) Is he on any medications? I would primarily like to rule out electrolyte disturbances, heart & kidney pathology. He needs a complete physical exam, blood investigations (complete blood count, ESR, electrolyte levels, thyroid, liver and kidney function tests, a glucose panel,lipid profile serum osmolality, vasopressin levels) a urine routine with electrolyte &creatinine levels in urine and osmolality. I would also do a chest xray, electrocardiogram and an echocardiogram. He seems to be in Fluid overload with edema (the swollen feet and hands) Orthostatic hypotension (dizziness when changing position from supine to standing) is due to pooling of blood in the extremities. This happens in electrolyte disturbances, heart failure, kidney failure or hormone (thyroid, adrenal, pituitary) imbalances. He needs medical attention right away. his continued plain water intake could worsen the current situation and make a bad situation worse. PLease see a physician right away. If seizures, drowsiness, slurred speech or decreased level of consciousness, low urine output, facial puffiness occurs, with breathing difficulty, visit the emergency right away. hope this helps. please get back to us for further queries. Wish you both good health