Lisinopril belongs to the class of medications known as angiotensin converting enzyme inhibitors, widely prescribed to manage chronic hypertension and protect renal function in diabetic individuals. By preventing the synthesis of angiotensin II, a potent vasoconstrictor, it allows blood vessels to dilate, effectively lowering systemic blood pressure and reducing the workload on the myocardium. A common, benign yet bothersome side effect is a persistent dry cough, which occurs due to the accumulation of bradykinin in the respiratory tract. Patients should be counseled never to abruptly discontinue therapy, as this can lead to rebound hypertension. Regular monitoring of serum potassium levels and creatinine is essential, as this class can alter renal hemodynamics and cause potassium retention.