An exception to this is those with very high blood pressure readings especially when there is poor organ function.[79] Initial assessment of the hypertensive people should include a complete history and physical examination. With the availability of 24-hour ambulatory blood pressure monitors and home blood pressure machines, the importance of not wrongly diagnosing those who have white coat hypertension has led to a change in protocols. In the United Kingdom, current best practice is to follow up a single raised clinic reading with ambulatory measurement, or less ideally with home blood pressure monitoring over the course of 7 days.[79] The United States Preventive Services Task Force also recommends getting measurements outside of the healthcare environment.[80] Pseudohypertension in the elderly or noncompressibility artery syndrome may also require consideration. This condition is believed to be due to calcification of the arteries resulting in abnormally high blood pressure readings with a blood pressure cuff while intra arterial measurements of blood pressure are normal.[81] Orthostatic hypertension is when blood pressure increases upon standing.[82]

Low blood pressure is diagnosed by a doctor when they check your blood pressure with a sphygmomanometer. For people who experience low blood pressure without other symptoms, it may only require regular monitoring by a doctor during routine exams, and medical treatment may not be necessary. If certain signs suggest an underlying condition, your doctor may recommend one or more of the following tests to diagnose a cause for your hypotension:

When healthy lifestyle changes alone do not control or lower high blood pressure, your doctor may change or update your treatment plan by prescribing medicines to treat your condition. These medicines act in different ways to lower blood pressure. When prescribing medicines, your doctor will also consider their effect on other conditions you might have, such as heart disease or kidney disease. Possible high blood pressure medicines include:


When blood pressure is measured, there are two numbers for each reading: for example, "120 over 80" is written as 120/80. This is because each heartbeat sends a pressure wave through the bloodstream. The higher number (systolic blood pressure) is the peak of the wave, when your heart contracts (the loud "thump" when you listen to your heartbeat). The lower number (diastolic blood pressure) is the lower "dip" or trough of the wave, when your heart relaxes.

Other causes of dehydration include exercise, sweating, fever, and heat exhaustion or heat stroke. Individuals with mild dehydration may experience only thirst and dry mouth. Moderate to severe dehydration may cause orthostatic hypotension (manifested by lightheadedness, dizziness, or fainting upon standing). Prolonged and severe dehydration can lead to shock, kidney failure, confusion, acidosis (too much acid in the blood), coma, and even death.
Lap band (gastric banding) surgery, also referred to as laparoscopic adjustable gastric banding (LAGB) is a surgical procedure in which an adjustable belt is placed around the upper portion of the stomach. Candidates for lap band surgery are generally individuals with a body mass index over 40 kg/m2, or are more than 45 kilograms over their ideal body weight. Side effects, risks, and complications from lap band surgery should be discussed with a surgeon or physician prior to the operation.
If your blood pressure is elevated, your doctor may request you have more readings over the course of a few days or weeks. A hypertension diagnosis is rarely given after just one reading. Your doctor needs to see evidence of a sustained problem. That’s because your environment can contribute to increased blood pressure, such as the stress you may feel by being at the doctor’s office. Also, blood pressure levels change throughout the day.

There was a time when the high blood pressure medication list was very short indeed. In the 1950s, reserpine was one of the few products on the market to treat hypertension. It is rarely used due to its numerous side effects and drug interactions. The peripheral adrenergic inhibitors work in the brain to block signals that tell blood vessels to constrict. They are mostly used when other high blood pressure medications fail to solve the problem. Guanadrel (Hylorel), guanethidine monosulfate (Ismelin), and reserpine (Serpasil) are peripheral adrenergic inhibitors.


Primary (or essential) hypertension is when the cause is unknown. The majority of hypertension cases are primary. When there is an underlying problem such as kidney disease or hormonal disorders that can cause hypertension, it is called secondary hypertension. When it is possible to correct the underlying cause, high blood pressure usually improves and may even return to normal.


If your blood pressure is above the normal range for up to 5 readings (taken at different visits), your doctor will likely diagnose you with high blood pressure. Sometimes the doctor may diagnose you after a fewer number of readings, depending on how high above normal your blood pressure is and if you have other medical conditions. Blood pressure tends to be at its highest during exercise, physical work, or stress, and lowest during sleep. Everyone can have a temporary increase in blood pressure at one time or another, which is why it's important to take multiple readings.
It occurs more often in older people who are taking a lot of medication. However, it can cause symptoms in younger people. There may be underlying medical conditions such as joint hypermobility syndrome, diabetes, parkinson’s disease, addison’s disease or autonomic failure. Dehydration, hunger, low body weight and deconditioning (being out of shape/unfit) can reduce blood pressure. 

It’s important to determine whether your low blood pressure is “a primary problem or secondary problem,” notes Lawrence. A primary problem means that the body’s reflexes are not working as they should. Secondary causes mean that the low blood pressure is a result of things like dehydration or the effects of certain medications. “Some anti-hypertensive [medications] are more likely to cause hypotension than others, and a lot of it is dose-dependent,” says Lawrence. “In most people, there will be some easily identifiable secondary cause, or some easy solution to what may even be a chronic problem that has no secondary cause, and that’s why it’s important to see your doctor, so they can make an appropriate assessment.”
The measurements must have been obtained from at least two careful readings on at least two different occasions. What does careful mean? The guidelines provide a six-step tutorial on how, exactly, to correctly measure a blood pressure, which, admittedly, is sorely needed. My patients often have their first blood pressure taken immediately after they have rushed in through downtown traffic, as they’re sipping a large caffeinated beverage. While we always knew this could result in a falsely elevated measurement, it is now officially poor clinical technique resulting in an invalid reading.
African-Americans are at greater risk of developing hypertension than people of other races. African-Americans develop high blood pressure earlier in life and have more difficulty achieving blood pressure goals. Some studies suggest that African-Americans may be more sensitive to salt than other races. For those who are genetically prone to salt sensitivity, a small amount (half-teaspoon) of salt can raise blood pressure by 5 mm Hg. Dietary factors and being overweight can also raise blood pressure.

We stimulate high-impact research. Our Trans-Omics for Precision Medicine (TOPMed) Program includes participants with high blood pressure, which may help us understand how genes contribute to differences in disease severity and how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over the next decade, including new efforts for studying high blood pressure.


Drinking too much alcohol is a risk factor for high blood pressure. The American Heart Association guidelines recommend the consumption of no more than two alcoholic drinks per day for men and no more than one drink a day for women. One drink is defined as one 12-ounce beer, 4 ounces of wine, 1.5 ounces of 80-proof spirits, or 1 ounce of 100-proof spirits. Adults who consume more than three drinks in one sitting temporarily increase their blood pressure. However, binge drinking can lead to long-term increased blood pressure.
High blood pressure is more common in older people. At age 45, more men have hypertension than women. By age 65, this is reversed and more women are affected. People with diabetes have a greater risk of hypertension than those without diabetes. Having a close family member with high blood pressure also increases your risk of developing it. About 60% of all people with diabetes also have hypertension.
Electrocardiogram (ECG): This tests the heart's electrical activity. This test is more commonly used for patients at high risk of heart problems, such as hypertension and elevated cholesterol levels. The initial ECG is called a baseline. Subsequent ECGs may be compared with the baseline to reveal changes which may point to coronary artery disease or thickening of the heart wall.
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
Wear a blood pressure monitor. This monitor is attached to you. You will be asked to wear it for 24 hours. The monitor is usually programmed to take blood pressure readings every 15 to 30 minutes all day and night while you go about your normal activities. The doctor will evaluate the results. In some cases, home blood pressure monitors may also be used to evaluate the effectiveness of your treatment.
Hypertension is diagnosed on the basis of a persistently high resting blood pressure. The American Heart Association recommends at least three resting measurements on at least two separate health care visits.[74] The UK National Institute for Health and Care Excellence recommends ambulatory blood pressure monitoring to confirm the diagnosis of hypertension if a clinic blood pressure is 140/90 mmHg or higher.[75]
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