Intermittent drowsiness in elder people is a frequent clinical picture caused by chronic medical illnesses, polypharmacy, dehydration, or physiological alterations connected to aging. Recurrent or unexplained hyponatremia should be thoroughly investigated, as it might suggest an underlying endocrine disorder. This case presents a rare but clinically important reason for recurrent hyponatremia stemming from hypopituitarism caused by a non-functioning pituitary macroadenoma.We report the case of a 67-year-old retired police officer who visited the general practice with a few days of lethargy, somnolence, and intermittent drowsiness. His medical history included type 2 diabetes mellitus, hypothyroidism, coronary heart disease, and previous episodes of hyponatremia. He was hospitalized with a referral letter for further assessment. The first tests ruled out hematological, metabolic, renal, hepatic, cardiac, and medication-related issues. An extensive endocrine evaluation was performed, including serum cortisol, adrenocorticotropic hormone (ACTH), gonadotropins, and magnetic resonance imaging of the pituitary gland.This case is important because it brings out hypopituitarism as an uncommon and often neglected cause of recurrent hyponatremia in the elderly, especially when the patients have multiple comorbidities that may hide the original diagnosis.Recurrent hyponatraemia must never be classified as idiopathic. The workup must include endocrine causes, especially secondary adrenal insufficiency, when the common aetiologies are ruled out. The timely diagnosis and adequate hormone replacement therapy may contribute to the fast clinical improvement and the prevention of the occurrence of possibly life-threatening complications.In the case of this patient, hyponatremia in the aged population was likely multifactorial and probably wrongly thought to be caused by the chronic disease or medications. Secondary adrenal insufficiency as a result of impaired pituitary function led to decreased cortisol-induced free water excretion that caused repeated hyponatremia and neurocognitive symptoms. The thorough evaluation and constant care of the patient were crucial in uncovering the hidden cause.The case presented here illustrates the necessity of detailed assessment of recurrent hyponatremia in the elderly and draws attention to hypopituitarism resulting from a non-functioning pituitary macroadenoma as an infrequent but curable cause. Timely identification through a holistic approach can dramatically enhance patients' outcomes.