High Blood Pressure (Hypertension)

Diagnosis

To diagnose high blood pressure, your health care provider examines you, asks about your medical history, and listens to your heart with a stethoscope. Blood pressure is measured using a cuff placed around your arm. It’s essential that the cuff fits correctly because an ill-fitting cuff can cause inaccurate readings.

A blood pressure reading measures two numbers:

• Systolic pressure (top number): Pressure in the arteries when the heart beats

• Diastolic pressure (bottom number): Pressure in the arteries between heartbeats

High blood pressure, or hypertension, is diagnosed when readings consistently reach 130/80 mm Hg or higher. The diagnosis usually relies on the average of two or more readings taken on separate occasions.

Blood pressure stages include:

• Stage 1 hypertension: Systolic 130–139 mm Hg or diastolic 80–89 mm Hg

• Stage 2 hypertension: Systolic 140 mm Hg or higher or diastolic 90 mm Hg or higher

• Isolated systolic hypertension: High top number with normal bottom number, common in adults over 65

Your provider may recommend tests to identify possible causes of high blood pressure or assess organ health.

Common diagnostic tests include:

• Ambulatory monitoring: Continuous measurement of blood pressure over 6 to 24 hours

• Lab tests: Blood and urine tests to check cholesterol, blood sugar, and kidney, liver, and thyroid function

• Electrocardiogram (ECG or EKG): Evaluates the heart’s electrical activity

• Echocardiogram: Uses sound waves to create images of the heart and assess how well it functions

Your provider might also ask you to monitor blood pressure at home. This helps track progress and determine how well treatment is working. The American Heart Association recommends using an upper arm cuff monitor for accurate readings. Wrist or finger monitors are not considered reliable.

Treatment

Managing high blood pressure often starts with lifestyle changes. Your health care provider may recommend:

• Eating a heart-healthy diet with reduced salt

• Exercising regularly

• Maintaining or achieving a healthy weight

• Limiting alcohol consumption

• Avoiding smoking

• Getting 7 to 9 hours of sleep each night

If lifestyle changes aren’t enough, medications may be prescribed to lower blood pressure. The treatment goal for most adults is below 130/80 mm Hg, especially if you have other conditions such as diabetes, kidney disease, or coronary artery disease.

Common medications include:

• Diuretics (water pills): Help remove excess sodium and water from the body. Examples include chlorthalidone and hydrochlorothiazide. Some may require potassium supplements or a potassium-sparing alternative.

• ACE inhibitors: Relax blood vessels by blocking a chemical that narrows them. Examples include lisinopril, benazepril, and captopril.

• ARBs (angiotensin II receptor blockers): Block the action of chemicals that tighten blood vessels. Examples include losartan and candesartan.

• Calcium channel blockers: Relax blood vessel muscles and sometimes slow the heart rate. Examples include amlodipine and diltiazem. Avoid grapefruit products while taking these medicines.

Other medications that may be used include:

• Alpha blockers: Reduce nerve signals that narrow blood vessels (e.g., doxazosin, prazosin)

• Alpha-beta blockers: Slow heart rate and relax blood vessels (e.g., carvedilol, labetalol)

• Beta blockers: Reduce heart workload and slow the heartbeat (e.g., atenolol, metoprolol)

• Aldosterone antagonists: Help treat resistant hypertension (e.g., spironolactone, eplerenone)

• Renin inhibitors: Reduce the production of renin, which helps regulate blood pressure (e.g., aliskiren)

• Vasodilators: Prevent artery walls from tightening (e.g., hydralazine, minoxidil)

• Central-acting agents: Stop the brain from signaling blood vessels to constrict (e.g., clonidine, guanfacine, methyldopa)

Always take medications as prescribed and never skip or stop them suddenly, as this can cause a rebound increase in blood pressure.

Treating Resistant Hypertension

Resistant hypertension occurs when blood pressure remains high despite taking three or more medications, including a diuretic, or if four or more medicines are required. Managing resistant hypertension may involve:

• Adjusting medication combinations or dosages

• Reviewing all medicines, including non-prescription drugs

• Checking for “white coat hypertension,” when readings are higher only in medical settings

• Reinforcing lifestyle changes such as diet and exercise

High Blood Pressure During Pregnancy

If you are pregnant and have high blood pressure, your health care team will help monitor and manage your condition to protect both you and your baby.

Potential Future Treatments

Researchers are studying renal denervation, a procedure that uses heat to disable specific nerves in the kidney that may contribute to resistant hypertension. Early results are mixed, and more research is needed to determine its effectiveness.