Hypertension is also known as “high blood pressure.” It is a condition in which blood flows through blood vessels at higher than normal pressures. Hypertension can lead to other heart diseases.
Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood. High blood pressure, also called hypertension, happens when this force is too high. Blood pressure is measured in millimeters of mercury (mmHg) and is designated by 2 numbers that are written in the following way: systolic pressure/diastolic pressure. For example, 120/80 mmHg is read as “120 over 80.”
Systolic pressure (the top or first number) is the blood pressure when the heart beats while pumping blood. Blood pressure is highest when the heart beats. Diastolic pressure (the bottom or second number) is the blood pressure when the heart is at rest between beats. The blood pressure falls when the heart rests.
Normal blood pressure for adults is defined as a systolic pressure below 120 mmHg and a diastolic pressure below 80 mmHg. It is normal for blood pressures to change when you sleep, wake up, or are excited or nervous. When you are active, it is normal for your blood pressure to increase. However, once the activity stops, your blood pressure returns to your normal baseline range.
Blood pressure normally increases with age and body size. Newborn babies often have very low blood pressure numbers that are considered normal for babies, while older teens have numbers similar to adults.
Abnormal increases in blood pressure are defined as having blood pressures higher than 120/80 mmHg. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 mmHg.
There are 2 main types of high blood pressure: primary and secondary high blood pressure. Primary, or essential, high blood pressure is the most common type of high blood pressure. This type of high blood pressure tends to develop over years as a person ages. Secondary high blood pressure is high blood pressure that is caused by another medical condition or use of certain medicines. This type usually resolves after the cause is treated or removed.
High blood pressure usually has no symptoms, but it can cause serious problems such as stroke, heart failure, heart attack, and kidney failure. Over time, consistently high blood pressure weakens and damages your blood vessels, which can lead to complications throughout the body.
Most cases of high blood pressure develop over many years, and, eventually, high blood pressure affects nearly everyone. Fortunately, high blood pressure can be easily detected. You can control high blood pressure through healthy lifestyle habits such as exercise and the DASH diet and taking medicines, if needed.
Symptoms of high blood pressure do not usually appear until the body is damaged from chronic high blood pressure, and most people with high blood pressure have no signs or symptoms, even if blood pressure readings reach dangerously high levels.
Rarely, people with high blood pressure may have headaches, shortness of breath or nosebleeds, but these signs and symptoms are not specific and usually do not occur until high blood pressure has reached a severe or life-threatening stage.
For most adults, there is no identifiable cause of high blood pressure. This type of high blood pressure, called primary (essential) hypertension, tends to develop gradually over many years. Changes, from genes or the environment, in the body’s normal functions may cause high blood pressure, including changes to fluid and salt balances in the body, nervous system activity, and blood vessel structure and function. Hypertension tends to run in families.
Unhealthy lifestyle habits can cause high blood pressure, including:
- high dietary sodium intake and sodium sensitivity
- drinking excess amounts of alcohol
- lack of physical activity
Research studies show that being overweight or obese can increase the resistance in the blood vessels, causing the heart to work harder and leading to high blood pressure.
Some people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:
- obstructive sleep apnea
- kidney problems
- adrenal gland tumors
- thyroid problems
- certain defects in blood vessels you are born with
- certain medications, such as birth control pills, cold remedies, decongestants, over-the-counter pain relievers, and some prescription drugs
- illegal drugs, such as cocaine and amphetamines
- alcohol abuse or chronic alcohol use
High blood pressure has many risk factors, including:
- Age. The risk of high blood pressure increases as you age.
- Race. High blood pressure is particularly common among blacks, often developing at an earlier age than it does in whites.
- Family history. High blood pressure tends to run in families.
- Being overweight or obese. The more you weigh, the more blood you need to supply oxygen and nutrients to your tissues. As the volume of blood circulated through your blood vessels increases, so does the pressure on your artery walls.
- Not being physically active. People who are inactive tend to have higher heart rates. The higher your heart rate, the harder your heart must work with each contraction and the stronger the force on your arteries. Lack of physical activity also increases the risk of being overweight.
- Using tobacco. Smoking and chewing tobacco immediately raise your blood pressure temporarily, and the chemicals in tobacco damage the lining of your artery walls. This can cause your arteries to narrow, increasing your blood pressure.
- Too much salt (sodium) in your diet. Too much sodium in your diet can cause your body to retain fluid, which increases blood pressure.
- Too little potassium in your diet. Potassium helps balance the amount of sodium in your cells. If you don't get enough potassium in your diet or retain enough potassium, you may accumulate too much sodium in your blood.
- Drinking too much alcohol. Over time, heavy drinking can damage your heart. If you drink alcohol, do so in moderation.
- Stress. High levels of stress can lead to a temporary increase in blood pressure.
- Pregnancy. Sometimes, pregnancy can contribute to high blood pressure.
To measure your blood pressure, your doctor or a specialist will usually place an inflatable arm cuff around your arm and measure your blood pressure using a pressure-measuring gauge.
A blood pressure reading, given in millimeters of mercury (mm Hg), has 2 numbers. The first, or upper, number measures the pressure in your arteries when your heart beats (systolic pressure). The second, or lower, number measures the pressure in your arteries between beats (diastolic pressure).
Blood pressure measurements fall into 4 general categories:
- Normal blood pressure. Your blood pressure is normal if it's below 120/80 mm Hg.
- Prehypertension. Prehypertension is a systolic pressure ranging from 120 to 139 mm Hg or a diastolic pressure ranging from 80 to 89 mm Hg. Prehypertension tends to get worse over time.
- Stage 1 hypertension. Stage 1 hypertension is a systolic pressure ranging from 140 to 159 mm Hg or a diastolic pressure ranging from 90 to 99 mm Hg.
- Stage 2 hypertension. More severe hypertension, stage 2 hypertension is a systolic pressure of 160 mm Hg or higher or a diastolic pressure of 100 mm Hg or higher.
Your health care provider usually takes 2–3 readings at several medical appointments to diagnose high blood pressure.
To prepare for the test:
- do not drink coffee or anything that contains caffeine or smoke cigarettes for 30 minutes prior to the test
- go to the bathroom before the test
- sit for 5 minutes before the test
Living With Hypertension
If you have high blood pressure, the best thing to do is to talk with your health care provider and take steps to control your blood pressure by making healthy lifestyle changes and taking medications, if any have been prescribed for you. The goal of hypertension treatment is to control blood pressure from getting to high and prevent complications related to ongoing high blood pressures.
You can help control your blood pressure by making these healthy lifestyle changes:
- Follow a healthy diet. The Dietary Approaches to Stop Hypertension (DASH) diet emphasizes fruits, vegetables, whole grains, poultry, fish and low-fat dairy foods. Get plenty of potassium, which can help prevent and control high blood pressure. Eat less saturated fat and trans fat. Eat less salt in your diet. Salt is found in many processed foods, so read food labels carefully.
- Be physically active. Regular physical activity can help lower your blood pressure, manage stress, reduce your risk of several health problems and keep your weight under control.
- Maintain a healthy weight. Keeping a healthy weight, or losing weight if you are overweight or obese, can help you control your high blood pressure and lower your risk of related health problems.
- Limit alcohol intake. Alcohol can raise your blood pressure. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger. One drink equals 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80-proof liquor.
Other lifestyle changes can improve your overall health, such as:
- not smoking
- geting plenty of sleep
- drinking more water
- managing stress
If high blood pressure cannot be controlled by lifestyle changes, along, medicines might be needed to control blood pressure. Blood pressure medicines work in different ways to stop or slow some of the body’s functions that cause high blood pressure. To lower and control blood pressure, many people take 2or more medicines. Medicines to lower blood pressure include:
- Diuretics (also called “water pills” or “fluid pills”). Diuretics flush excess sodium from your body, which reduces the amount of fluid in your blood and helps to lower your blood pressure. Diuretics are often used with other high blood pressure medicines, sometimes in one combined pill. Common diuretics include acetazolamide (Diamox), amiloride (Midamor), bumetanide (Bumex), chlorothiazide (Diuril), chlorthalidone (Thalitone), ethacrynic acid (Edecrin), furosemide (Lasix), hydrochlorothiazide (Microzide, HCTZ), metolazone (Zaroxolyn), torsemide (Demadex), and triamterene (Dyrenium, Dyazide, Maxzide).
- Beta blockers. These help your heart beat slower and with less force. As a result, your heart pumps less blood through your blood vessels, which can help to lower your blood pressure. Common beta blockers include metoprolol (Toprol XL, Lopressor), carvedilol (Coreg), bisoprolol (Zebeta), betaxolol (Kerlone), nebivolol (Bystolic), and propranolol (Inderal, Pronol).
- Angiotensin-converting enzyme (ACE) inhibitors. Angiotensin-II is a hormone that narrows blood vessels, increasing blood pressure. ACE converts angiotensin I to angiotensin II. ACE inhibitors block this process, which stops the production of Angiotensin II, lowering blood pressure. Common ACE inhibitors include benazepril (Lotensin, Lotensin HCT), captopril (Capoten, Capozide), enalapril (Vasotec, Vaseretic), fosinopril (Monopril, Monopril HCT), lisinopril (Prinivil, Prinzide, Zestril, Zestoretic), moexipril (Univasc, Uniretic), quinapril (Accupril, Accuretic, Quinaretic), ramipril (Altace), and trandolapril (Mavik, Tarka).
- Angiotensin II receptor blockers (ARBs). These agents block angiotensin II hormone from binding with receptors in the blood vessels. When angiotensin II is blocked, the blood vessels do not constrict or narrow, which can lower your blood pressure. Common angiotensin receptor II blockers include azilsartan (Edarbi), candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), telmisartan (Micardis, Twynsta), and valsartan (Diovan).
- Calcium channel blockers. These agents keep calcium from entering the muscle cells of your heart and blood vessels. This allows blood vessels to relax, which can lower your blood pressure. Common calcium channel blockers include nifedipine (Adalat, Nifedical, Procardia), amlodipine (Novasc), verapamil (Calan, Isoptin, Covera, Verelan), and diltiazem (Cardizem).
- Central-acting agents. These agents act in the brain to decrease nerve signals that narrow blood vessels, which can lower blood pressure. Examples of central-acting agents include clonidine (Catapres, Kapvay), guanfacine (Intuniv, Tenex) and methyldopa.
- Vasodilators. These agents relax the muscles in blood vessel walls, which can lower blood pressure. Common vasodilators include doxazosin (Cardura), prazosin (Minipress), terazosin (Hytrin), clonidine (Catapres), hydralazine (Bidil, Hydra-Zide), and minoxidil.