The document discusses antihypertensive drugs used to treat hypertension, defined as high blood pressure exceeding 140/90 mm Hg. It categorizes various types of antihypertensives including ACE inhibitors, angiotensin receptor blockers, calcium channel blockers, diuretics, and sympatholytics, detailing their mechanisms, side effects, and uses. Additionally, it highlights considerations for treating hypertension in special populations such as pregnant women and diabetic patients.