High blood pressure is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease.
Blood pressure is determined both by the amount of blood your heart pumps and the amount of resistance to blood flow in your arteries. The more blood your heart pumps and the narrower your arteries, the higher your blood pressure.
You can have high blood pressure (hypertension) for years without any symptoms. Even without symptoms, damage to blood vessels and your heart continues and can be detected. Uncontrolled high blood pressure increases your risk of serious health problems, including heart attack and stroke.
High blood pressure generally develops over many years, and it affects nearly everyone eventually. Fortunately, high blood pressure can be easily detected. And once you know you have high blood pressure, you can work with your doctor to control it.
Tests and diagnosis
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 two 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 four 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.
Both numbers in a blood pressure reading are important. But after age 60, the systolic reading is even more significant. Isolated systolic hypertension is a condition in which the diastolic pressure is normal (less than 90 mm Hg) but systolic pressure is high (greater than 140 mm Hg). This is a common type of high blood pressure among people older than 60.
Your doctor will likely take two to three blood pressure readings each at three or more separate appointments before diagnosing you with high blood pressure. This is because blood pressure normally varies throughout the day, and sometimes specifically during visits to the doctor, a condition called white coat hypertension. Your blood pressure generally should be measured in both arms to determine if there is a difference. Your doctor may ask you to record your blood pressure at home and at work to provide additional information.
Your doctor may suggest a 24-hour blood pressure monitoring test called ambulatory blood pressure monitoring. The device used for this test measures your blood pressure at regular intervals over a 24-hour period and provides a more accurate picture of blood pressure changes over an average day and night. However, these devices aren't available in all medical centers, and they're rarely reimbursed.
If you have any type of high blood pressure, your doctor will review your medical history and conduct a physical examination.
Your doctor may also recommend routine tests, such as a urine test (urinalysis), blood tests, a cholesterol test and an electrocardiogram — a test that measures your heart's electrical activity. Your doctor may also recommend additional tests, such as an echocardiogram, to check for more signs of heart disease.
Taking your blood pressure at home
An important way to check if your blood pressure treatment is working, or to diagnose worsening high blood pressure, is to monitor your blood pressure at home. Home blood pressure monitors are widely available and inexpensive, and you don't need a prescription to buy one. Talk to your doctor about how to get started. Home blood pressure monitoring isn't a substitute for visits to your doctor, and home blood pressure monitors may have some limitations
Treatments and drugs
Changing your lifestyle can go a long way toward controlling high blood pressure. Your doctor may recommend you eat a healthy diet with less salt, exercise regularly, quit smoking and maintain a healthy weight. But sometimes lifestyle changes aren't enough.
In addition to diet and exercise, your doctor may recommend medication to lower your blood pressure.
Your blood pressure treatment goal depends on how healthy you are.
Blood pressure treatment goals*
*Although 120/80 mm Hg or lower is the ideal blood pressure goal, doctors are unsure if you need treatment (medications) to reach that level.
Less than150/90 mm Hg
If you're a healthy adult age 60 or older
Less than140/90 mm Hg
If you're a healthy adult younger than age 60
Less than140/90 mm Hg
If you have chronic kidney disease, diabetes or coronary artery disease or are at high risk of coronary artery disease
If you're age 60 or older, and use of medications produces lower systolic blood pressure (such as less than 140 mm Hg), your medications won't need to be changed unless they cause negative effects to your health or quality of life.
Also, people older than 60 commonly have isolated systolic hypertension — when diastolic pressure is normal but systolic pressure is high.
The category of medication your doctor prescribes depends on your blood pressure measurements and your other medical problems.
Medications to treat high blood pressure
- Thiazide diuretics. Diuretics, sometimes called water pills, are medications that act on your kidneys to help your body eliminate sodium and water, reducing blood volume.
Thiazide diuretics are often the first, but not the only, choice in high blood pressure medications. Thiazide diuretics include hydrochlorothiazide (Microzide), chlorthalidone and others.
If you're not taking a diuretic and your blood pressure remains high, talk to your doctor about adding one or replacing a drug you currently take with a diuretic. Diuretics or calcium channel blockers may work better for blacks and older people than do angiotensin-converting enzyme (ACE) inhibitors alone. A common side effect of diuretics is increased urination.
- Beta blockers. These medications reduce the workload on your heart and open your blood vessels, causing your heart to beat slower and with less force. Beta blockers include acebutolol (Sectral), atenolol (Tenormin) and others.
When prescribed alone, beta blockers don't work as well, especially in older adults, but may be effective when combined with other blood pressure medications.
- Angiotensin-converting enzyme (ACE) inhibitors. These medications — such as lisinopril (Zestril), benazepril (Lotensin), captopril (Capoten) and others — help relax blood vessels by blocking the formation of a natural chemical that narrows blood vessels. People with chronic kidney disease may benefit from having an ACE inhibitor as one of their medications.
- Angiotensin II receptor blockers (ARBs). These medications help relax blood vessels by blocking the action, not the formation, of a natural chemical that narrows blood vessels. ARBs include candesartan (Atacand), losartan (Cozaar) and others. People with chronic kidney disease may benefit from having an ARB as one of their medications.
- Calcium channel blockers. These medications — including amlodipine (Norvasc), diltiazem (Cardizem, Tiazac, others) and others — help relax the muscles of your blood vessels. Some slow your heart rate. Calcium channel blockers may work better for older people and blacks than do ACE inhibitors alone.
Grapefruit juice interacts with some calcium channel blockers, increasing blood levels of the medication and putting you at higher risk of side effects. Talk to your doctor or pharmacist if you're concerned about interactions.
- Renin inhibitors. Aliskiren (Tekturna) slows down the production of renin, an enzyme produced by your kidneys that starts a chain of chemical steps that increases blood pressure.
Tekturna works by reducing the ability of renin to begin this process. Due to a risk of serious complications, including stroke, you shouldn't take aliskiren with ACE inhibitors or ARBs.
Additional medications sometimes used to treat high blood pressure
If you're having trouble reaching your blood pressure goal with combinations of the above medications, your doctor may prescribe:
- Alpha blockers. These medications reduce nerve impulses to blood vessels, reducing the effects of natural chemicals that narrow blood vessels. Alpha blockers include doxazosin (Cardura), prazosin (Minipress) and others.
- Alpha-beta blockers. In addition to reducing nerve impulses to blood vessels, alpha-beta blockers slow the heartbeat to reduce the amount of blood that must be pumped through the vessels. Alpha-beta blockers include carvedilol (Coreg) and labetalol (Trandate).
- Central-acting agents. These medications prevent your brain from signaling your nervous system to increase your heart rate and narrow your blood vessels. Examples include clonidine (Catapres, Kapvay), guanfacine (Intuniv, Tenex) and methyldopa.
- Vasodilators. These medications, including hydralazine and minoxidil, work directly on the muscles in the walls of your arteries, preventing the muscles from tightening and your arteries from narrowing.
- Aldosterone antagonists. Examples are spironolactone (Aldactone) and eplerenone (Inspra). These drugs block the effect of a natural chemical that can lead to salt and fluid retention, which can contribute to high blood pressure.
To reduce the number of daily medication doses you need, your doctor may prescribe a combination of low-dose medications rather than larger doses of one single drug. In fact, two or more blood pressure drugs often are more effective than one. Sometimes finding the most effective medication or combination of drugs is a matter of trial and error.
Lifestyle changes to treat high blood pressure
No matter what medications your doctor prescribes to treat your high blood pressure, you'll need to make lifestyle changes to lower your blood pressure.
Your doctor may recommend several lifestyle changes, including:
- Eating a healthier diet with less salt (the Dietary Approaches to Stop Hypertension, or DASH, diet)
- Exercising regularly
- Quitting smoking
- Limiting the amount of alcohol you drink
- Maintaining a healthy weight or losing weight if you're overweight or obese
Resistant hypertension: When your blood pressure is difficult to control
If your blood pressure remains stubbornly high despite taking at least three different types of high blood pressure drugs, one of which usually should be a diuretic, you may have resistant hypertension. People who have controlled high blood pressure but are taking four different types of medications at the same time to achieve that control also are considered to have resistant hypertension. The possibility of a secondary cause of the high blood pressure generally should be reconsidered.
Having resistant hypertension doesn't mean your blood pressure will never get lower. In fact, if you and your doctor can identify what's behind your persistently high blood pressure, there's a good chance you can meet your goal with the help of treatment that's more effective.
Your doctor or hypertension specialist can evaluate whether the medications and doses you're taking for your high blood pressure are appropriate. You may have to fine-tune your medications to come up with the most effective combination and doses. Adding an aldosterone antagonist such as spironolactone (Aldactone) often leads to control of resistant hypertension. Some experimental therapies such as catheter-based radiofrequency ablation of renal sympathetic nerves (renal denervation) and electrical stimulation of carotid sinus baroreceptors are being studied.
In addition, you and your doctor can review medications you're taking for other conditions. Some medications, foods or supplements can worsen high blood pressure or prevent your high blood pressure medications from working effectively. Be open and honest with your doctor about all the medications or supplements you take.
If you don't take your high blood pressure medications exactly as directed, your blood pressure can pay the price. If you skip doses because you can't afford the medications, because you have side effects or because you simply forget to take your medications, talk to your doctor about solutions. Don't change your treatment without your doctor's guidance.