High Blood Pressure Facts
Each time the heart beats, it creates a certain amount of pressure (force) against artery walls. High blood pressure is when the force is significantly greater than normal. Hypertension is another name for sustained high blood pressure, as tension increases within the walls.
Blood pressure is highest when blood is moving out of the heart into arteries. This is the systolic pressure—the top number in a blood pressure measurement. Pressure is lowest when the heart relaxes between beats (and blood is moving into the heart). This is the diastolic pressure, or bottom number. Pressure is expressed as millimeters (mm) of mercury (Hg).
High blood pressure facts:
High blood pressure numbers that define hypertension are 130 mm Hg or higher systolic pressure or 80 mm Hg or higher diastolic pressure, or both, based on the 2017 American College of Cardiology/American Heart Association (ACA/AHA) guideline.
Causes of high blood pressure include both lifestyle factors and genetics, but the disease is multifactorial.
There are no symptoms of high blood pressure—it is physically measured with a blood pressure cuff.
High blood pressure damages blood vessels, which weakens the heart and kidneys and causes chronic heart failure and kidney disease. The damage also creates an environment for atherosclerosis, a hardening and narrowing of the arteries that greatly increases the risk of stroke and heart attack.
A heart-healthy lifestyle and high blood pressure medications can control most cases of hypertension to target levels.
Nearly half (45%) of people who know they have hypertension do not have it under control.
Primary and secondary high blood pressure are the two main forms of the disease. Primary high blood pressure is the most common form, affecting 85% of people with hypertension. A combination of factors—faulty genes, environmental factors, and others—bring on primary high blood pressure, also known as essential hypertension.
Secondary hypertension is a result, or secondary effect, of other primary medical conditions, such as kidney disease.
High blood pressure is categorized as stage 1, 2 or 3:
Stage 1: 130-139 (top number) or 80-89 (bottom number)
Stage 2: 140 or higher or 90 or higher
Stage 3: higher than 180 and/or higher than 120
The two other categories are:
Normal: lower than 120/80
Elevated (prehypertension): 120-129 and lower than 80
High blood pressure afflicts nearly half the United States population age 20 and older, based on the 2017 ACA/AHA guideline. This is about 103 million U.S. adults.
Epidemiology studies have found:
- Age is a strong predictor of hypertension. Among the estimated 100 million U.S. adults with high blood pressure, 65% are 60 and older, 32% are 40 to 59, and 7% are 18 to 39.
About the same number of women and men have high blood pressure, suggesting biological sex is not a risk factor.
More non-Hispanic black adults have high blood pressure than non-Hispanic white, Hispanic, and Asian American adults.
Primary hypertension and hypertensive renal disease (high blood pressure due to blocked kidney artery) is listed as the cause of death for about 33,000 people a year in the United States—among the top 15 causes of death. However, this does not account for deaths due to heart disease (leading cause of death) or stroke (fifth-leading cause of death), for which high blood pressure is a major contributing cause. From 2005 to 2015, the number of deaths due to high blood pressure increased 37%. High blood pressure also shortens life expectancy by about five years.
Hypertensive crisis—when blood pressure quickly rises to 180/120 or higher—can cause stroke, heart attack, kidney and eye damage, aortic dissection, and memory loss, among other complications. Symptoms of hypertensive crisis include severe headache, shortness of breath, loss of consciousness, chest pain, nosebleed, and severe anxiety.
High blood pressure is contributing factor for the following conditions:
Kidney disease or kidney failure
High blood pressure is what many heart and vascular specialists refer to as the ‘silent killer’ because there are no symptoms (except for hypertensive crisis), but life-threatening blood vessel damage is happening.
The biggest burdens of high blood pressure include:
Four-fold higher risk of dying from stroke
Three-fold higher risk of dying from heart disease
Doctor visits—as a population, Americans make 55 million doctor visits annually for blood pressure treatment
Medical expense—an estimated $53 billion annually in the United States
Primary high blood pressure is a multifactorial disease. This means it takes the combined effect of several factors to cause high blood pressure, rather than a single cause and effect. Genetics and family history play a role, as high blood pressure tends to run in families.
New research shows that a specific genetic abnormality that prevents blood vessels from dilating (expanding) normally can cause high blood pressure, even in the absence of kidney disease. Although the study was in mice, it could explain how high blood pressure might start in people who do not have kidney disease. Large scale genomic studies have identified dozens of genes associated with high blood pressure.
Lifestyle factors and behaviors that increase one’s risk include:
Drinking heavily and frequently
High sodium diet
A high blood pressure diagnosis requires several blood pressure measurements to record and confirm it. (The 2017 ACA/AHA guideline is more than two measurements at more than two doctor visits.) Healthcare providers commonly measure the arterial pressure in the upper arm, but both arms and legs may be measured as well.
Doctors or other healthcare professionals order additional tests to determine (if possible) an underlying cause and look for signs of organ damage.
Additional tests may include:
Urine tests for kidney function
Kidney and possibly heart ultrasound (echocardiogram)
EKG (electrocardiogram, or ECG)
Blood tests for measuring cholesterol, creatinine and potassium levels
Sleep apnea evaluation
For secondary hypertension, treating the underlying problem, such as kidney disease or an adrenal gland tumor, may return blood pressure to normal. There is no cure for primary hypertension, but patients can usually control it with lifestyle changes and, if necessary, high blood pressure medication.
The treatment goal is blood pressure lower than 130/80 mm Hg, because this is shown to reduce the risk of stroke and heart attack.
Effective behavior modifications, which can also help prevent high blood pressure, include:
Eating a heart-healthy diet including less alcohol and less than 1,500 mg sodium/day
Not smoking/quitting smoking
Losing weight for overweight or obese patients
American Heart Association guidelines recommend medication for adults with:
Stage 1 hypertension and 65 years of age or older
Stage 1 hypertension and a history or risk of cardiovascular disease (CVD), or stage 1 and patient has diabetes or chronic kidney disease
Stage 2 or 3 hypertension
Blood pressure medication options include:
ACE inhibitors, which relax blood vessels
Beta blockers, which decrease heart rate
Calcium channel blockers, which relax blood vessels and decrease heart rate
Angiotensin II receptor blockers, which relax blood vessels
Diuretics (water pills), which decreases blood volume and pressure
High blood pressure is a preventable and treatable disease, but only half of people with high blood pressure have it under control. Learn more about the long-term effects of high blood pressure and the Million Hearts campaign for cardiovascular disease awareness and prevention.