In these cases, oral medications are used to lower the BP gradually over 24 to 48 hours.In hypertensive emergency, there is evidence of direct damage to one or more organs. The most affected organs include the brain, kidney, heart and lungs, producing symptoms which may include confusion, drowsiness, chest pain and breathlessness. In hypertensive emergency, the blood pressure must be reduced more rapidly to stop ongoing organ damage, however, there is a lack of randomized controlled trial evidence for this approach. Pregnancy
Hypertension occurs in approximately 8–10% of pregnancies. Two blood pressure measurements six hours apart of greater than 140/90 mm Hg are diagnostic of hypertension in pregnancy. High blood pressure in pregnancy can be classified as pre-existing hypertension, gestational hypertension, or pre-eclampsia.Pre-eclampsia is a serious condition of the second half of pregnancy and following delivery characterised by increased blood pressure and the presence of protein in the urine. It occurs in about 5% of pregnancies and is responsible for approximately 16% of all maternal deaths globally. Pre-eclampsia also doubles the risk of death of the baby around the time of birth. Usually there are no symptoms in pre-eclampsia and it is detected by routine screening. When symptoms of pre-eclampsia occur the most common are headache, visual disturbance (often "flashing lights"), vomiting, pain over the stomach, and swelling.
These medications may be used alone or in combination (ACE inhibitors and ARBs are not recommended for use in combination); the latter option may serve to minimize counter-regulatory mechanisms that act to restore blood pressure values to pre-treatment levels. Most people require more than one medication to control their hypertension. Medications for blood pressure control should be implemented by a stepped care approach when target levels are not reached.Previously beta-blockers such as atenolol were thought to have similar beneficial effects when used as first-line therapy for hypertension. However, a Cochrane review that included 13 trials found that the effects of beta-blockers are inferior to that of other antihypertensive medications in preventing cardiovascular disease. Resistant hypertension
Resistant hypertension is defined as high blood pressure that remains above a target level, in spite of being prescribed three or more antihypertensive drugs simultaneously with different mechanisms of action. Failing to take prescribed medications as directed is an important cause of resistant hypertension. Resistant hypertension may also result from chronically high activity of the autonomic nervous system, an effect known as neurogenic hypertension. Electrical therapies that stimulate the baroreflex are being studied as an option for lowering blood pressure in people in this situation.Some common secondary causes of resistant hypertension include obstructive sleep apnea, pheochromocytoma, renal artery stenosis, coarctation of the aorta, and primary aldosteronism. As many as one in five people with resistant hypertension have primary aldosteronism, which is a treatable and sometimes curable condition.