Blood pressure changes throughout the day and varies from person to person. Various factors affect blood pressure, including your body position, breathing rhythm, stress level, physical activity, medications, what you eat or drink, and the time of the day (blood pressure is usually lowest at night when you sleep and rises when you wake up). In healthy individuals, your body responds and adapts to these changes to keep your blood pressure within a normal range. This ensures that vital organs, such as your brain and kidneys, receive a constant blood flow and nutrient supply.
Your doctor may suggest that you check your blood pressure at home. The easiest way to do this is to use a digital blood pressure monitor. You can get a monitor from your local drug store, hospital, clinic or online. Your doctor can help you find a monitor that is right for you and show you how to use it. Many pharmacies and grocery stores also have in-store monitors that you can use for free.
Obesity: As body weight increases, the blood pressure rises. Obesity is defined as having a body mass index (BMI) greater than 30 kg/m. A BMI of 25-30 kg/m is considered overweight (BMI=weight in pounds x 703/ height in inches). Being overweight increases the risk of high blood pressure. Healthcare professionals recommend that all individuals who are obese and have high blood pressure lose weight until they are within 15% of their healthy body weight.

^ Qaseem A, Wilt TJ, Rich R, Humphrey LL, Frost J, Forciea MA (17 January 2017). "Pharmacologic Treatment of Hypertension in Adults Aged 60 Years or Older to Higher Versus Lower Blood Pressure Targets: A Clinical Practice Guideline From the American College of Physicians and the American Academy of Family Physicians". Annals of Internal Medicine. 166 (6): 430–437. doi:10.7326/M16-1785. PMID 28135725.
Hypertension defined as elevated blood pressure over several visits affects 1% to 5% of children and adolescents and is associated with long term risks of ill-health.[89] Blood pressure rises with age in childhood and, in children, hypertension is defined as an average systolic or diastolic blood pressure on three or more occasions equal or higher than the 95th percentile appropriate for the sex, age and height of the child. High blood pressure must be confirmed on repeated visits however before characterizing a child as having hypertension.[89] Prehypertension in children has been defined as average systolic or diastolic blood pressure that is greater than or equal to the 90th percentile, but less than the 95th percentile.[89] In adolescents, it has been proposed that hypertension and pre-hypertension are diagnosed and classified using the same criteria as in adults.[89]
Effective lifestyle modification may lower blood pressure as much as an individual antihypertensive medication. Combinations of two or more lifestyle modifications can achieve even better results.[87] There is considerable evidence that reducing dietary salt intake lowers blood pressure, but whether this translates into a reduction in mortality and cardiovascular disease remains uncertain.[96] Estimated sodium intake ≥6g/day and <3g/day are both associated with high risk of death or major cardiovascular disease, but the association between high sodium intake and adverse outcomes is only observed in people with hypertension.[97] Consequently, in the absence of results from randomized controlled trials, the wisdom of reducing levels of dietary salt intake below 3g/day has been questioned.[96]

The new guidelines also encourage additional monitoring, using a wearable digital monitor that continually takes blood pressure readings as you go about your life, or checked with your own cuff at home. This additional monitoring can help to tease out masked hypertension (when the blood pressure is normal in our office, but high the rest of the time) or white coat hypertension (when the blood pressure is high in our office, but normal the rest of the time). There are clear, helpful directions for setting patients up with a home blood pressure monitor, including a recommendation to give people specific instructions on when not to check blood pressure (within 30 minutes of smoking, drinking coffee, or exercising) and how to take a measurement correctly (seated comfortably, using the correct size cuff). The home blood pressure cuff should first be validated (checked in the office, for accuracy).
The portal venous system contains veins coming from the stomach, intestine, spleen, and pancreas. These veins merge into the portal vein, which branches into smaller vessels and travel through the liver. Portal hypertension occurs when there is an increase in the blood pressure within the portal venous system. When the vessels in the liver are blocked due to liver damage, blood cannot flow properly through the liver. This causes high blood pressure in the portal system.
Recent updates to guidelines from the American Heart Association and the American College of Cardiology changed the definition of high blood pressure or hypertension for most people. High blood pressure is now generally defined as 130 or higher for the first number, or 80 or higher for the second number (previously it was 140/90). However, there are important considerations for older adults in deciding whether to start treatment for high blood pressure, including other health conditions and overall fitness. If your blood pressure is above 130/80, your doctor will evaluate your health to determine what treatment is needed to balance risks and benefits in your particular situation.
The range of systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure ranges between 60 and 80 mm Hg. Current guidelines define normal blood pressure range as lower than 120/80. Blood pressures over 130/80 are considered high. High blood pressure increases the risk of damaging the arteries, which leads to the development of:
Blood spots in the eyes : Blood spots in the eyes (subconjunctival hemorrhage) are more common in people with diabetes or high blood pressure, but neither condition causes the blood spots. Floaters in the eyes are also not related to high blood pressure. However, an eye doctor (ophthalmologist) may be able to detect damage to the optic nerve caused by untreated high blood pressure.   
Hypertension in African-Americans tends to occur earlier in life and tends to be more severe. Plus, some medications that work to lower blood pressure in other ethnicities may have limited effect on African-Americans. Thiazide diuretics (such as HCTZ) or a calcium channel blocker are recommended first choices along with the possible add-on of a second drug from either the ACE inhibitor class or the angiotensin II receptor blocker group.

Normal blood pressure is below 120/80. New guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC) published in November of 2017 consider blood pressure elevated between 120/80 and 129/80. High blood pressure or hypertension is now classified as stage 1 if your systolic reading falls between 130 and 139 or your diastolic reading is between 80 and 89. A measure of 140/90 or higher is now considered stage 2 hypertension. A hypertensive crisis is defined as a systolic rate over 180 or a diastolic rate above 120. An elevated blood pressure means that the heart must work harder to pump blood. High blood pressure can also damage the walls of the arteries. Over time, hypertension increases the risk of heart disease, kidney disease, and stroke. It is estimated that one in three adults in America are affected by hypertension.

The first chemical for hypertension, sodium thiocyanate, was used in 1900 but had many side effects and was unpopular.[152] Several other agents were developed after the Second World War, the most popular and reasonably effective of which were tetramethylammonium chloride, hexamethonium, hydralazine, and reserpine (derived from the medicinal plant Rauwolfia serpentina). None of these were well tolerated.[159][160] A major breakthrough was achieved with the discovery of the first well-tolerated orally available agents. The first was chlorothiazide, the first thiazide diuretic and developed from the antibiotic sulfanilamide, which became available in 1958.[152][161] Subsequently, beta blockers, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers, and renin inhibitors were developed as antihypertensive agents.[158]


Effective lifestyle modification may lower blood pressure as much as an individual antihypertensive medication. Combinations of two or more lifestyle modifications can achieve even better results.[87] There is considerable evidence that reducing dietary salt intake lowers blood pressure, but whether this translates into a reduction in mortality and cardiovascular disease remains uncertain.[96] Estimated sodium intake ≥6g/day and <3g/day are both associated with high risk of death or major cardiovascular disease, but the association between high sodium intake and adverse outcomes is only observed in people with hypertension.[97] Consequently, in the absence of results from randomized controlled trials, the wisdom of reducing levels of dietary salt intake below 3g/day has been questioned.[96]
Strong Heart Study. Since 1988, the NHLBI has supported the Strong Heart Study (SHS), the largest epidemiologic study of American Indians ever conducted. The SHS aims to estimate the impact of heart and blood vessel diseases and to assess how common and significant standard risk factors are in this community. Thirteen tribes and communities in four states participate in the study. Visit Strong Heart Study for more information.
To make an official diagnosis of high blood pressure you will need to see your doctor. Often your blood pressure will be checked on at least two different visits, at different times of the day. Your doctor may ask you to keep a blood pressure log for a short time in order to see your overall blood pressure trends. If your blood pressure is consistently over 134/80, your doctor will work with you to determine the best regimen for treating your high blood pressure.
The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.
Quitting smoking. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart [PDF – 2MB]. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, you can call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).
There are even more medication types that can lower blood pressure. Some of these are alpha blockers, vasodilators, and central alpha agonists. Your doctor may prescribe these medications if other medications have been ineffective or if you have another condition along with hypertension. Side effects can include fast pulse, palpitations, dizziness, diarrhea, or headaches.
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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