Several classes of antihypertensive agents are recommended, with the choice depending on the cause of the hypertensive crisis, the severity of the elevation in blood pressure, and the usual blood pressure of the person before the hypertensive crisis. In most cases, the administration of intravenous sodium nitroprusside injection which has an almost immediate antihypertensive effect, is suitable (but in many cases not readily available). Besides, nitroprusside runs a risk of cyanide poisoning. Other intravenous agents like nitroglycerine, nicardipine, labetalol, fenoldopam or phentolamine can also be used, but all have a delayed onset of action (by several minutes) compared to sodium nitroprusside.

In addition, non-pharmacological treatment could be considered in cases of resistant malignant hypertension due to end stage kidney failure, such as surgical nephrectomy, laparoscopic nephrectomy, and renal artery embolization in cases of anesthesia risk.

It is also important that the blood pressure is lowered smoothly, not too abruptly. The initial goal in hypertensive emergencies is to reduce the pressure by no more than 25% (within minutes to 1 or 2 hours), and then toward a level of 160/100 mm Hg within a total of 2–6 hours. Excessive reduction in blood pressure can precipitate coronary, cerebral, or renal ischemia and, possibly, infarction.

The diagnosis of a hypertensive emergency is not based solely on an absolute level of blood pressure, but also on the typical blood pressure level of the patient before the hypertensive crisis occurs. Individuals with a history of chronic hypertension may not tolerate a "normal" blood pressure.

In terms of treatment for renovascular hypertension surgical revascularization versus medical therapy for atherosclerosis, it is not clear if one option is better than the other according to a 2014 Cochrane review; balloon angioplasty did show a small improvement in blood pressure .

Surgery can include percutaneous surgical revascularization, and also nephrectomy or autotransplantation, and the individual may be given beta-adrenergic blockers. Early therapeutic intervention is important if ischemic nephropathy is to be prevented. Inpatient care is necessary for the management of hypertensive urgencies, quick intervention is required to prevent further damage to the kidneys.

The initial aim of treatment in hypertensive crises is to rapidly lower the diastolic pressure to about 100 to 105 mmHg; this goal should be achieved within two to six hours, with the maximum initial fall in BP not exceeding 25 percent of the presenting value. This level of BP control will allow gradual healing of the necrotizing vascular lesions. More aggressive hypotensive therapy is both unnecessary and may reduce the blood pressure below the autoregulatory range, possibly leading to ischemic events (such as stroke or coronary disease).

Once the BP is controlled, the person should be switched to medication by mouth, with the diastolic pressure being gradually reduced to 85 to 90 mmHg over two to three months. The initial reduction to a diastolic pressure of approximately 100 mmHg is often associated with a modest worsening of renal function; this change, however, is typically transient as the vascular disease tends to resolve and renal perfusion improves over one to three months. Antihypertensive therapy should not be withheld in this setting unless there has been an excessive reduction in BP. A change in medication, however, is indicated if the decline in renal function is temporally related to therapy with an angiotensin (ACE) converting enzyme inhibitor or angiotensin II receptor blocker, which can interfere with renal autoregulation and produce acute renal failure in patients with bilateral renal artery stenosis. (See "Renal effects of ACE inhibitors in hypertension".)

Several parenteral antihypertensive agents are most often used in the initial treatment of malignant hypertension.

- Nitroprusside – an arteriolar and venous dilator, given as an intravenous infusion. Nitroprusside acts within seconds and has a duration of action of only two to five minutes. Thus, hypotension can be easily reversed by temporarily discontinuing the infusion, providing an advantage over the drugs listed below. However, the potential for cyanide toxicity limits the prolonged use of nitroprusside, particularly in patients with renal insufficiency.

- Nicardipine – an arteriolar dilator, given as an intravenous infusion.

- Clevidipine – a short-acting dihydropyridine calcium channel blocker. It reduces blood pressure without affecting cardiac filling pressures or causing reflex tachycardia.

- Labetalol – an alpha- and beta-adrenergic blocker, given as an intravenous bolus or infusion. Bolus followed by infusion.

- Fenoldopam – a peripheral dopamine-1 receptor agonist, given as an intravenous infusion.

- Oral agents — A slower onset of action and an inability to control the degree of BP reduction has limited the use of oral antihypertensive agents in the therapy of hypertensive crises. They may, however, be useful when there is no rapid access to the parenteral medications described above. Both sublingual nifedipine and sublingual captopril can substantially lower the BP within 10 to 30 minutes in many patients. A more rapid response is seen when liquid nifedipine is swallowed.

The major risk with oral agents is ischemic symptoms (e.g., angina pectoris, myocardial infarction, or stroke) due to an excessive and uncontrolled hypotensive response. Thus, their use should generally be avoided in the treatment of hypertensive crises if more controllable drugs are available.

Regular physical exercise reduces blood pressure. The UK National Health Service advises 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity per week to help prevent hypertension.

Prostacyclin (prostaglandin I) is commonly considered the most effective treatment for PAH. Epoprostenol (synthetic prostacyclin) is given via continuous infusion that requires a semi-permanent central venous catheter. This delivery system can cause sepsis and thrombosis. Prostacyclin is unstable, and therefore has to be kept on ice during administration. Since it has a half-life of 3 to 5 minutes, the infusion has to be continuous, and interruption can be fatal. Other prostanoids have therefore been developed. Treprostinil can be given intravenously or subcutaneously, but the subcutaneous form can be very painful. An increased risk of sepsis with intravenous Remodulin has been reported by the CDC. Iloprost is also used in Europe intravenously and has a longer half life. Iloprost was the only inhaled form of prostacyclin approved for use in the US and Europe, until the inhaled form of treprostinil was approved by the FDA in July 2009.

Certain medications, including NSAIDs (Motrin/Ibuprofen) and steroids can cause hypertension. Other medications include extrogens (such as those found in oral contraceptives with high estrogenic activity), certain antidepressants (such as venlafaxine), buspirone, carbamazepine, bromocriptine, clozapine, and cyclosporine.

High blood pressure that is associated with the sudden withdrawal of various antihypertensive medications is called rebound hypertension. The increases in blood pressure may result in blood pressures greater than when the medication was initiated. Depending on the severity of the increase in blood pressure, rebound hypertension may result in a hypertensive emergency. Rebound hypertension is avoided by gradually reducing the dose (also known as "dose tapering"), thereby giving the body enough time to adjust to reduction in dose. Medications commonly associated with rebound hypertension include centrally-acting antihypertensive agents, such as clonidine and methyl-dopa.

Other herbal or "natural products" which have been associated with hypertension include ma huang, St John's wort, and licorice.

The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.

A major aim of treatment is to prevent, limit, or reverse target organ damage by lowering the person's high blood pressure to reduce the risk of cardiovascular disease and death. Treatment with antihypertensive medications may be required to control the high blood pressure.

Medium-term (and less well-demonstrated) treatments of hypotension include:

- Blood sugar control (80–150 by one study)

- Early nutrition (by mouth or by tube to prevent ileus)

- Steroid support

The medical care of patients with hypertensive heart disease falls under 2 categories—

- Treatment of hypertension

- Prevention (and, if present, treatment) of heart failure or other cardiovascular disease

Coronary ischemia can be treated but not cured.

By changing lifestyle, further blockages can be prevented. A change in lifestyle, mixed with prescribed medication, can improve health.

Prognosis of individuals with renovascular hypertension is not easy to determine. Those with atherosclerotic renal artery disease have a high risk of mortality, furthermore those who also have renal dysfunction have a higher mortality risk.

However, the majority of renovascular diseases can be improved with surgery.

The medication midodrine can benefit people with orthostatic hypotension, The main side-effect is piloerection ("goose bumps"). Fludrocortisone is also used, although based on more limited evidence.

A number of other measures have slight evidence to support their use indomethacin, fluoxetine, dopamine antagonists, metoclopramide, domperidone, monoamine oxidase inhibitors with tyramine (can produce severe hypertension), oxilofrine, potassium chloride, and yohimbine.

According to JNC 7, BP goals should be as follows :

- Less than 140/90mm Hg in patients with uncomplicated hypertension

- Less than 130/85mm Hg in patients with diabetes and those with renal disease with less than 1g/24-hour proteinuria

- Less than 125/75mm Hg in patients with renal disease and more than 1 g/24-hour proteinuria

Patients with hypertensive encephalopathy who are promptly treated usually recover without deficit. However, if treatment is not administered, the condition can lead to death.

It has been suggested that vitamin D deficiency is associated with cardiovascular risk factors. It has been observed that individuals with a vitamin D deficiency have higher systolic and diastolic blood pressures than average. Vitamin D inhibits renin secretion and its activity, it therefore acts as a "negative endocrine regulator of the renin-angiotensin system". Hence, a deficiency in vitamin D leads to an increase in renin secretion. This is one possible mechanism of explaining the observed link between hypertension and vitamin D levels in the blood plasma.

Also, some authorities claim that potassium might both prevent and treat hypertension.

Nitrates such as nitroglycerin are often used as part of the initial therapy for ADHF.

Another option is nesiritide, although it should only be considered if conventional therapy has been ineffective or contraindicated as it is much more expensive than nitroglycerine and has not been shown to be of any greater benefit.

Initial therapy of acute decompensated heart failure usually includes some combination of a vasodilator such as nitroglycerin, a loop diuretic such as furosemide, and non-invasive positive pressure ventilation (NIPPV).

Even if symptoms of heart failure are not present, medications can be used to treat the symptoms that are being experienced. These medicines work to control these symptoms as well as treat other health problems that might be present. They can work to improve the quality of life, slow down the progression of heart failure and reduce the risk for other complications that can occur due to heart failure. It is very important to take proper medicines exactly as prescribed by the physician.

A number of different medications are required for people who are experiencing heart failure. Common types of medications that are prescribed for heart failure patients include ACE inhibitors, vasodilators, beta blockers, aspirin, calcium channel blockers, and cholesterol lowering medications such as statins. Depending on the type of damage a patient has suffered and the underlying cause of the heart failure, any of these drug classes or a combination of them can be prescribed. Patients with heart pumping problems will use a different medication combination than those who are experiencing problems with the heart's ability to fill properly during diastole. Potentially dangerous drug interactions can occur when different drugs mix together and work against each other.

The treatment for hypotension depends on its cause. Chronic hypotension rarely exists as more than a symptom. Asymptomatic hypotension in healthy people usually does not require treatment. Adding electrolytes to a diet can relieve symptoms of mild hypotension. A morning dose of caffeine can also be effective. In mild cases, where the patient is still responsive, laying the person in dorsal decubitus (lying on the back) position and lifting the legs increases venous return, thus making more blood available to critical organs in the chest and head. The Trendelenburg position, though used historically, is no longer recommended.

Hypotensive shock treatment always follows the first four following steps. Outcomes, in terms of mortality, are directly linked to the speed that hypotension is corrected. Still-debated methods are in parentheses, as are benchmarks for evaluating progress in correcting hypotension. A study on septic shock provided the delineation of these general principles. However, since it focuses on hypotension due to infection, it is not applicable to all forms of severe hypotension.

1. Volume resuscitation (usually with crystalloid)

2. Blood pressure support with a vasopressor (all seem equivalent with respect to risk of death, with norepinephrine possibly better than dopamine). Trying to achieve a mean arterial pressure (MAP) of greater than 70 mmHg does not appear to result in better outcomes than trying to achieve a MAP of greater than 65 mm Hg in adults.

3. Ensure adequate tissue perfusion (maintain SvO2 >70 with use of blood or dobutamine)

4. Address the underlying problem (i.e., antibiotic for infection, stent or CABG (coronary artery bypass graft surgery) for infarction, steroids for adrenal insufficiency, etc...)

The best way to determine if a person will benefit from fluids is by doing a passive leg raise followed by measuring the output from the heart.

Angioplasty with or without stenting is the best option for the treatment of renal artery stenosis due to fibromuscular dysplasia.

It is initially treated with medications, including diuretics, and medications for blood pressure control. When high-grade renal artery stenosis is documented and blood pressure cannot be controlled with medication, or if renal function deteriorates, surgery may be resorted to. The most commonly used procedure is a minimally-invasive angioplasty with or without stenting. It is unclear if this approach yields better results than the use of medications alone. It is a relatively safe procedure. If all else fails and the kidney is thought to be worsening hypertension and revascularization with angioplasty or surgery does not work, then surgical removal of the affected kidney (nephrectomy) may significantly improve high blood pressure.

Apart from treating underlying reversible causes (e.g., stopping or reducing certain medications), there are a number of measures that can improve the symptoms of orthostatic hypotension and prevent episodes of syncope. Even small increases in the blood pressure may be sufficient to maintain blood flow to the brain on standing.

In people who do not have a diagnosis of high blood pressure, drinking 2–3 liters of fluid a day and taking 10 grams of salt can improve symptoms, by maximizing the amount of fluid in the bloodstream. Another strategy is keeping the head of the bed slightly elevated. This reduces the return of fluid from the limbs to the kidneys at night, thereby reducing nighttime urine production and maintaining fluid in the circulation. Various measures can be used to improve the return of blood to the heart: the wearing of compression stockings and exercises ("physical counterpressure manoeuvres" or PCMs) that can be undertaken just before standing up (e.g., leg crossing and squatting).

It is recommended that blood pressure typically be reduced to less than 140/90 mmHg. The diastolic blood pressure however should not be lower than 60 mmHg. Beta blockers are recommended first line for this use.

Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high blood pressure, however, is a major risk factor for coronary artery disease, stroke, heart failure, peripheral vascular disease, vision loss, chronic kidney disease, and dementia.

High blood pressure is classified as either primary (essential) high blood pressure or secondary high blood pressure. About 90–95% of cases are primary, defined as high blood pressure due to nonspecific lifestyle and genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, excess body weight, smoking, and alcohol use. The remaining 5–10% of cases are categorized as secondary high blood pressure, defined as high blood pressure due to an identifiable cause, such as chronic kidney disease, narrowing of the kidney arteries, an endocrine disorder, or the use of birth control pills.

Blood pressure is expressed by two measurements, the systolic and diastolic pressures, which are the maximum and minimum pressures, respectively. For most adults, normal blood pressure at rest is within the range of 100–130 millimeters mercury (mmHg) systolic and 60–80 mmHg diastolic. For most adults, high blood pressure is present if the resting blood pressure is persistently at or above 130/90 or 140/90 mmHg. Different numbers apply to children. Ambulatory blood pressure monitoring over a 24-hour period appears more accurate than office-based blood pressure measurement.

Lifestyle changes and medications can lower blood pressure and decrease the risk of health complications. Lifestyle changes include weight loss, decreased salt intake, physical exercise, and a healthy diet. If lifestyle changes are not sufficient then blood pressure medications are used. Up to three medications can control blood pressure in 90% of people. The treatment of moderately high arterial blood pressure (defined as >160/100 mmHg) with medications is associated with an improved life expectancy. The effect of treatment of blood pressure between 130/80 mmHg and 160/100 mmHg is less clear, with some reviews finding benefit and others finding unclear benefit. High blood pressure affects between 16 and 37% of the population globally. In 2010 hypertension was believed to have been a factor in 18% of all deaths (9.4 million globally).

Secondary hypertension results from an identifiable cause. Kidney disease is the most common secondary cause of hypertension. Hypertension can also be caused by endocrine conditions, such as Cushing's syndrome, hyperthyroidism, hypothyroidism, acromegaly, Conn's syndrome or hyperaldosteronism, renal artery stenosis (from atherosclerosis or fibromuscular dysplasia), hyperparathyroidism, and pheochromocytoma. Other causes of secondary hypertension include obesity, sleep apnea, pregnancy, coarctation of the aorta, excessive eating of liquorice, excessive drinking of alcohol, and certain prescription medicines, herbal remedies, and illegal drugs such as cocaine and methamphetamine. Arsenic exposure through drinking water has been shown to correlate with elevated blood pressure.