patients with newly diagnosed hyponatremia. Moreover, analysis of osmolality and electrolyte levels both in the blood and in the urine is necessary to determine the exact etiology. For example, hypovolemic patients are likely to have very low levels of urinary sodium, whereas someone like the patient presented in this case, who has adrenal insufciency, will have higher levels of urinary sodium, indicating sodium wasting. Serum potassium levels are important, in particular, to assess adrenal func­tion since adrenal or aldosterone receptor diseases have the opposite effects on sodium and potassium. Treatment, importantly, also varies based on the etiology of hyponatremia. Volume repletion is generally needed in cases of hypovolemia, while water restriction is encouraged with euvolemic and hypervolemic hyponatremia [10]. In cases of euvolemic hyponatremia, psychogenic polydipsia needs to be ruled out– usually by assessing urine osmolality and, as needed, doing a water depriva­tion test which will result in a prompt increase in urine osmolality [11]. Frequently, in the hospital setting, SIADH becomes the “default” diagnosis even before the entire workup has been completed, which, like in this case, increases the probability that subtler presentations of other conditions may be missed. Another thing worth mentioning is that, in this case, the patient already had a history of hypothyroidism, which predisposes her to other autoimmune endocrine disorders, such as adrenal insufciency. Moreover, hypothyroidism itself could be a cause of hyponatremia in some patients, although this patient’s current TSH level is normal, so it is not a likely cause in her. Obtaining hormone levels if there is any suspicion of endocrine disease needs to be part of the workup since the condition can progress and become life-threatening [12]. For instance, had this patient not been diagnosed, it is feasible that in the near future, she could have developed an adrenal crisis. Treatment of adrenal insufciency depends on the hormones that are affected (which depends on the zones of the adrenal gland that are affected) but typically involve glucocorti­coids, such as hydrocortisone or prednisone, as well as udrocortisone. Hormonal supplementation should lead to the normalization of electrolyte levels.