hello thank you for trusting HCM dear since when you re suffering from this problem??are you diabetic?have you passing more urine???dear possible causes are diabetes mellitus . other possibilities like diabetes insipidus, psychogenic polydipsia ,profuse sweating, dehydration, hypokalemia, diabetic Ketoacidosis etc... dear you need to be evaluated with blood and urine tests to confirm the cause.please consult your doctor he will examine and treat you accordingly. I think I answered to your question if you have more questions feel free to ask. take care