There is general agreement as to which antihypertensive drugs are appropriate for initial therapy in most patients with hypertension. The major options are Thiazide-type diuretics,Angiotensin-converting enzyme (ACE) inhibitors/angiotensin II receptor blockers (ARBs),Calcium channel blockers.Recommendations concerning the use of particular agents for the initial treatment of hypertension will be presented here. The diagnosis and evaluation of hypertension, as well as a discussion of goal blood pressure in the treatment of hypertension. Antihypertensive drugs are frequently used by patients and may influence conduct of anaesthesia.Relatively few drug classes are used to treat hypertension, the newest of which are direct renin inhibitors.The renin–angiotensin system is targeted at different points by many of the commonly used antihypertensive drugs.Antihypertensive drugs have diverse indications, both cardiac and non-cardiac.