<prompt> Answer this question truthfullyWhat is hypoaldosteronism, and how can it be distinguished from other medical conditions?  <response>: <reason> Hypoaldosteronism must be differentiated from other diseases that cause hypotension and muscle weakness such as Addisons disease, salt-depletion nephritis, myopathies, celiac disease, Peutz-Jeghers syndrome, anorexia nervosa, syndrome of inappropriate anti-diuretic hormone SIADH, neurofibromatosis, porphyria cutanea tarda, and bronchogenic carcinoma. In addition, measurement of plasma renin activity PRA, serum aldosterone, and serum cortisol is used to differentiate among various subtypes of hypoaldosteronism. 