The eyes may show retinal hemorrhage or an exudate. Papilledema must be present before a diagnosis of malignant hypertension can be made. The brain shows manifestations of increased intracranial pressure, such as headache, vomiting, and/or subarachnoid or cerebral hemorrhage. Patients will usually suffer from left ventricular dysfunction. The kidneys will be affected, resulting in hematuria, proteinuria, and acute renal failure. It differs from other complications of hypertension in that it is accompanied by papilledema. This can be associated with hypertensive retinopathy.

Other signs and symptoms can include:

- Chest pain

- Arrhythmias

- Headache

- Epistaxis

- Dyspnea

- Faintness or vertigo

- Severe anxiety

- Agitation

- Altered mental status

- Paresthesias

- Vomiting

Chest pain requires immediate lowering of blood pressure (such as with sodium nitroprusside infusions), while urgencies can be treated with oral agents, with the goal of lowering the mean arterial pressure (MAP) by 20% in 1–2 days with further reduction to "normal" levels in weeks or months. The former use of oral nifedipine, a calcium channel blocker, has been strongly discouraged as it has led to excessive falls in blood pressure with serious and fatal consequences.

Sometimes, the term hypertensive emergency is also used as a generic term, comprising both hypertensive "emergency", as a specific term for a serious and urgent condition of elevated blood pressure, and hypertensive urgency, as a specific term of a less serious and less urgent condition (the terminology hypertensive "crisis" is usually used in this sense).

The term hypertensive emergency is primarily used as a specific term for a hypertensive crisis with a diastolic blood pressure greater than or equal to 120 mmHg or systolic blood pressure greater than or equal to 180 mmHg. Hypertensive emergency differs from hypertensive crisis in that, in the former, there is evidence of acute organ damage.

Hypertension with certain specific additional signs and symptoms may suggest secondary hypertension, i.e. hypertension due to an identifiable cause. For example, Cushing's syndrome frequently causes truncal obesity, glucose intolerance, moon face, a hump of fat behind the neck/shoulder (referred to as a buffalo hump), and purple abdominal stretch marks. Hyperthyroidism frequently causes weight loss with increased appetite, fast heart rate, bulging eyes, and tremor. Renal artery stenosis (RAS) may be associated with a localized abdominal bruit to the left or right of the midline (unilateral RAS), or in both locations (bilateral RAS). Coarctation of the aorta frequently causes a decreased blood pressure in the lower extremities relative to the arms, or delayed or absent femoral arterial pulses. Pheochromocytoma may cause abrupt ("paroxysmal") episodes of hypertension accompanied by headache, palpitations, pale appearance, and excessive sweating.

Hypertension is rarely accompanied by symptoms, and its identification is usually through screening, or when seeking healthcare for an unrelated problem. Some with high blood pressure report headaches (particularly at the back of the head and in the morning), as well as lightheadedness, vertigo, tinnitus (buzzing or hissing in the ears), altered vision or fainting episodes. These symptoms, however, might be related to associated anxiety rather than the high blood pressure itself.

On physical examination, hypertension may be associated with the presence of changes in the optic fundus seen by ophthalmoscopy. The severity of the changes typical of hypertensive retinopathy is graded from I–IV; grades I and II may be difficult to differentiate. The severity of the retinopathy correlates roughly with the duration or the severity of the hypertension.

Severely elevated blood pressure (equal to or greater than a systolic 180 or diastolic of 110—sometimes termed malignant or accelerated hypertension) is referred to as a "hypertensive crisis", as blood pressure at this level confers a high risk of complications. People with blood pressures in this range may have no symptoms, but are more likely to report headaches (22% of cases) and dizziness than the general population. Other symptoms accompanying a hypertensive crisis may include visual deterioration due to retinopathy, breathlessness due to heart failure, or a general feeling of malaise due to kidney failure. Most people with a hypertensive crisis are known to have elevated blood pressure, but additional triggers may have led to a sudden rise.

A "hypertensive emergency" is diagnosed when there is evidence of direct damage to one or more organs as a result of severely elevated blood pressure greater than 180 systolic or 120 diastolic. This may include hypertensive encephalopathy, caused by brain swelling and dysfunction, and characterized by headaches and an altered level of consciousness (confusion or drowsiness). Retinal papilledema and/or fundal bleeds and exudates are another sign of target organ damage. Chest pain may indicate heart muscle damage (which may progress to myocardial infarction) or sometimes aortic dissection, the tearing of the inner wall of the aorta. Breathlessness, cough, and the coughing up of blood-stained sputum are characteristic signs of pulmonary edema, the swelling of lung tissue due to left ventricular failure an inability of the left ventricle of the heart to adequately pump blood from the lungs into the arterial system. Rapid deterioration of kidney function (acute kidney injury) and microangiopathic hemolytic anemia (destruction of blood cells) may also occur. In these situations, rapid reduction of the blood pressure is mandated to stop ongoing organ damage. In contrast there is no evidence that blood pressure needs to be lowered rapidly in hypertensive urgencies where there is no evidence of target organ damage and over aggressive reduction of blood pressure is not without risks. Use of oral medications to lower the BP gradually over 24 to 48h is advocated in hypertensive urgencies.

Hypertensive encephalopathy is most commonly encountered in young and middle-aged people who have hypertension. Overall, the condition is rare even among people with hypertension. Studies report that from 0.5 to 15% of people with malignant hypertension develop hypertensive encephalopathy. With the development of methods for detection and treatment of hypertension, hypertensive encephalopathy has been becoming more rare.

Symptoms of hypertensive encephalopathy typically start to occur 12–48 hours after a sudden and sustained increase in blood pressure. The first manifestation of these symptoms is a severe headache. Headache occurs in greater than 75% of patients. The patient becomes restless. Alterations in consciousness may follow several hours later, which include impaired judgement and memory, confusion, somnolence and stupor. If the condition is not treated, these neurological symptoms may worsen and ultimately turn into a coma. Other symptoms may include increased irritability, vomiting, diplopia, seizures, twitching and myoclonus of the limbs. Alterations in vision (vision blurring, hemivisual field defects, color blindness, cortical blindness) are common. They occur in 4 out of 11 cases (Jellinek et al. 1964). Hemiparesis, intracerebral hemorrhage, aphasia may also occur, but they are less common.

Symptoms of renovascular hypertension include the following:

- High blood pressure (early age)

- Kidney dysfunction

- Narrowing of arteries elsewhere in the body

- Pulmonary edema

A hypertensive urgency is a clinical situation in which blood pressure is very high (e.g., ≥180/≥110 mmHg) with minimal or no symptoms, and "no" signs or symptoms indicating acute organ damage. This contrasts with a hypertensive emergency where severe blood pressure is accompanied by evidence of progressive organ or system damage.

Renovascular hypertension (or "renal hypertension") is a condition in which high blood pressure is caused by the kidneys' hormonal response to narrowing of the arteries supplying the kidneys. When functioning properly this hormonal axis regulates blood pressure. Due to low local blood flow, the kidneys mistakenly increases blood pressure of the entire circulatory system. It is a form of secondary hypertension - a form of hypertension whose cause is identifiable.

A recent classification recommends blood pressure criteria for defining normal blood pressure, prehypertension, hypertension (stages I and II), and isolated systolic hypertension, which is a common occurrence among the elderly. These readings are based on the average of seated blood pressure readings that were properly measured during 2 or more office visits. In individuals older than 50 years, hypertension is considered to be present when a person's blood pressure is consistently at least 140 mmHg systolic or 90 mmHg diastolic. Patients with blood pressures over 130/80 mmHg along with Type 1 or Type 2 diabetes, or kidney disease require further treatment.

Resistant hypertension is defined as the failure to reduce blood pressure to the appropriate level after taking a three-drug regimen. Guidelines for treating resistant hypertension have been published in the UK, and US.

Hypertensive encephalopathy (HE) is general brain dysfunction due to significantly high blood pressure. Symptoms may include headache, vomiting, trouble with balance, and confusion. Onset is generally sudden. Complications can include seizures, posterior reversible encephalopathy syndrome, and bleeding in the back of the eye.

In hypertensive encephalopathy, generally the blood pressure is greater than 200/130 mmHg. Occasionally it can occur at a BP as low as 160/100 mmHg. This can occur in kidney failure, those who rapidly stop blood pressure medication, pheochromocytoma, and people on a monoamine oxidase inhibitor (MAOI) who eats foods with tyramine. When it occurs in pregnancy it is known as eclampsia. The diagnosis requires ruling out other possible causes.

The condition is generally treated with medications to relatively rapidly lower the blood pressure. This may be done with labetalol or sodium nitroprusside given by injection into a vein. In those who are pregnant, magnesium sulfate may be used. Other treatments may include anti seizure medications.

Hypertensive encephalopathy is uncommon. It is believed to occur more often in those without easy access to health care. The term was first used by Oppenheimer and Fishberg in 1928. It is classified as a type of hypertensive emergency.

Because of the ubiquity of arsenic in ground water supplies and its effect on cardiovascular health, low dose arsenic poisoning should be inferred as a part of the pathogenesis of idiopathic hypertension. Idiopathic and essential are both somewhat synonymous with primary hypertension. Arsenic exposure has also many of the same signs of primary hypertension such as headache, somnolence,

confusion, proteinuria

visual disturbances, and nausea and vomiting

Essential hypertension (also called primary hypertension or idiopathic hypertension) is the form of hypertension that by definition has no identifiable cause. It is the most common type of hypertension, affecting 95% of hypertensive patients, it tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Prevalence of essential hypertension increases with age, and individuals with relatively high blood pressure at younger ages are at increased risk for the subsequent development of hypertension.

Hypertension can increase the risk of cerebral, cardiac, and renal events.

The ABCDE mnemonic can be used to help determine a secondary cause of hypertension

- A: Accuracy, Apnea, Aldosteronism

- B: Bruits, Bad Kidney

- C: Catecholamines, Coarctation of the Aorta, Cushing's Syndrome

- D: Drugs, Diet

- E: Erythropoietin, Endocrine Disorders

White coat hypertension, more commonly known as white coat syndrome, is a phenomenon in which patients exhibit a blood pressure level above the normal range, in a clinical setting, though they don't exhibit it in other settings. It is believed that the phenomenon is due to anxiety that those afflicted experience during a clinic visit.

The patient's daytime ambulatory blood pressure is used as a reference as it takes into account ordinary levels of daily stress. Many problems have been incurred in the diagnosis and treatment of white coat hypertension.

The term "masked hypertension" can be used to describe the contrasting phenomenon, where a patient's blood pressure is above the normal range during daily living, although it isn't above the normal range when the patient is in a clinic setting.

The changes in hypertensive retinopathy result from damage and adaptive changes in the arterial and arteriolar circulation in response to the high blood pressure.

In a hypertensive urgency blood pressure should be lowered carefully to ≤160/≤100 mmHg over a period of hours to days, this can often be done as an outpatient. There is limited evidence regarding the most appropriate rate of blood pressure reduction, although it is recommended that mean arterial pressure should be lowered by no more than 25 to 30 percent over the first few hours. There is also limited evidence about the best drugs in hypertensive urgencies, oral, short-acting agent such as captopril, labetalol, or clonidine have been used. Sublingual nifedipine is contraindicated in hypertensive urgencies and should "not" be used. Acute administration of drugs should be followed by several hours of observation to ensure that blood pressure does not fall too much. Aggressive dosing with intravenous drugs or oral agents which lowers blood pressure too rapidly carries risk; conversely there is no evidence that failure to rapidly lower blood pressure in a hypertensive urgency is associated with any increased short-term risk.

In general, individuals with white coat hypertension have lower morbidity than patients with sustained hypertension, but higher morbidity than the clinically normotensive.

However, it should be remembered that all the established published trials on the consequences of high blood pressure and the benefits of treating are based on one-time measurement in clinical settings rather than the generally slightly lower readings obtained from ambulatory recordings.

The debate and conflicting ideas revolve around whether or not it would be feasible to treat white coat hypertension, as there still is no conclusive evidence that a temporary rise in blood pressure during office visits has an adverse effect on health.

In fact, many cross sectional studies have shown that "target-organ damage (as exemplified by left ventricular hypertrophy) is less in white-coat hypertensive patients than in sustained hypertensive patients even after the allowance has been made for differences in clinic pressure". Many believe that patients with "white coat" hypertension do not require even very small doses of antihypertensive therapy as it may result in hypotension, but must still be careful as patients may show signs of vascular changes and may eventually develop hypertension. Even patients with established hypertension that is well-controlled based on home blood pressure monitoring may experience elevated readings during office visits.

Several other diseases can result in retinopathy that can be confused with hypertensive retinopathy. These include diabetic retinopathy, retinopathy due to autoimmune disease, anemia, radiation retinopathy, and central retinal vein occlusion.

Signs and symptoms of chronic kidney disease, including loss of appetite, nausea, vomiting, itching, sleepiness or confusion, weight loss, and an unpleasant taste in the mouth, may develop.

Hypertensive kidney disease is a medical condition referring to damage to the kidney due to chronic high blood pressure. HN can be divided into two types: benign and malignant. Benign nephrosclerosis is common in individuals over the age of 60 where malignant nephrosclerosis is uncommon and affects 1-5% of individuals with high blood pressure, that have diastolic blood pressure passing 130 mm Hg. It should be distinguished from renovascular hypertension, which is a form of secondary hypertension. In addition, HN can be referred to as hypertensive nephrosclerosis, benign nephrosclerosis, and nephroangiosclerosis.

Pseudohypertension, also known as pseudohypertension in the elderly, noncompressibility artery syndrome, and Osler's sign of pseudohypertension is a falsely elevated blood pressure reading obtained through sphygmomanometry due to calcification of blood vessels which cannot be compressed. There is normal blood pressure when it is measured from within the artery. This condition however is associated with significant cardiovascular disease risk.

Because the stiffened arterial walls of arteriosclerosis do not compress with pressure normally, the blood pressure reading is theoretically higher than the true intra-arterial measurement.

To perform the test, one first inflates the blood pressure cuff above systolic pressure to obliterate the radial pulse. One then attempts to palpate the radial artery, a positive test is if it remains palpable as a firm "tube".

It occurs frequently in the elderly irrespective of them being hypertensive, and has moderate to modest intraobserver and interobserver agreement. It is also known as "Osler's maneuver".

The sign is named for William Osler.

The symptoms and signs of hypertensive heart disease will depend on whether or not it is accompanied by heart failure. In the absence of heart failure, hypertension, with or without enlargement of the heart (left ventricular hypertrophy) is usually symptomless.

Symptoms, signs and consequences of Congestive heart failure can include:

- Fatigue

- Irregular pulse or palpitations

- Swelling of feet and ankles

- Weight gain

- Nausea

- Shortness of breath

- Difficulty sleeping flat in bed (orthopnea)

- Bloating and abdominal pain

- Greater need to urinate at night

- An enlarged heart (cardiomegaly)

- Left ventricular hypertrophy and left ventricular remodeling

- Diminished coronary flow reserve and silent myocardial ischemia

- Coronary heart disease and accelerated atherosclerosis

- Heart Failure With Normal Left Ventricular Ejection Fraction (HFNEF), often termed diastolic heart failure

- Atrial fibrillation, other cardiac arrhythmias, or sudden cardiac death

Heart failure can develop insidiously over time or patients can present acutely with acute heart failure or acute decompensated heart failure and pulmonary edema due to sudden failure of pump function of the heart. Sudden failure can be precipitated by a variety of causes, including myocardial ischemia, marked increases in blood pressure, or cardiac arrhythmias.

Patients can present with sudden increase in blood pressure, acute confusional state, headaches, vomiting, and seizure. Retinal hemorrhages and hard exudates may be present on funduscopic exam. Hypertensive leukoencephalopathy may have concurrent cardiac ischemia and hematuria.

Other conditions can share features with hypertensive heart disease and need to be considered in the differential diagnosis. For example:

- Coronary artery disease or ischemic heart disease due to atherosclerosis

- Hypertrophic cardiomyopathy

- Left ventricular hypertrophy in athletes

- Congestive heart failure or heart failure with normal ejection fraction due to other causes

- Atrial fibrillation or other disorders of cardiac rhythm due to other causes

- Sleep apnea