What Is High Blood Pressure and Why Does It Matter?
High blood pressure (hypertension) occurs when the force of blood against artery walls is consistently too high, typically 130/80 mmHg or above. This extra pressure strains your heart, damages blood vessels, and increases risk of heart attack, stroke, kidney disease, and other serious health problems.
Your blood pressure consists of two numbers: systolic pressure (top number) measures the force when your heart beats, while diastolic pressure (bottom number) measures the force between beats. Normal blood pressure is below 120/80 mmHg. Elevated blood pressure is 120-129 systolic with diastolic below 80. Stage 1 hypertension is 130-139/80-89 mmHg, and Stage 2 is 140/90 mmHg or higher. A hypertensive crisis is 180/120 mmHg or higher, requiring immediate medical attention.
Nearly half of American adults have high blood pressure, yet many don't know it because hypertension rarely causes noticeable symptoms until significant damage has occurred. This is why regular blood pressure screening is crucial. Untreated hypertension damages arteries throughout your body, making them less elastic and more prone to blockages. Over time, this increases risk of heart attack by 2-3 times, stroke by 3-4 times, and can lead to heart failure, kidney failure, vision loss, and cognitive decline.
What Causes High Blood Pressure?
About 90-95% of hypertension cases have no single identifiable cause (primary hypertension) and develop gradually due to genetics, aging, and lifestyle factors. The remaining 5-10% results from underlying conditions like kidney disease, sleep apnea, or hormonal disorders (secondary hypertension).
Primary hypertension develops through a complex interaction of genetic predisposition and environmental factors. Family history plays a significant role—if your parents have hypertension, you're more likely to develop it. Age is another major factor, as blood vessels naturally stiffen with time. Race also matters: African Americans develop hypertension earlier and experience more severe complications. Lifestyle factors that contribute include excessive sodium intake, inadequate potassium, physical inactivity, obesity, chronic stress, and excessive alcohol consumption.
Secondary hypertension has identifiable underlying causes including kidney disease, sleep apnea, thyroid disorders, adrenal gland tumors, certain medications (birth control pills, decongestants, NSAIDs), and illegal drugs like cocaine and amphetamines. This type often appears suddenly and causes higher blood pressure than primary hypertension. Identifying and treating the underlying condition can often resolve secondary hypertension. Your doctor may investigate secondary causes if you develop high blood pressure before age 30 or after age 55, or if blood pressure suddenly worsens or doesn't respond to multiple medications.
How Is High Blood Pressure Diagnosed?
Hypertension is diagnosed through multiple blood pressure readings taken on different occasions, not from a single measurement. Your doctor may use office measurements, home monitoring, or 24-hour ambulatory monitoring to confirm consistently elevated readings before making a diagnosis.
Accurate diagnosis requires proper measurement technique. You should sit quietly for 5 minutes before measurement, avoid caffeine and exercise for 30 minutes prior, and have your arm supported at heart level. Your doctor should take at least two readings at each visit and average them. Many doctors now recognize 'white coat hypertension' (elevated readings only in medical settings) and 'masked hypertension' (normal readings in office but elevated at home), which is why home blood pressure monitoring has become increasingly important for accurate diagnosis.
Once hypertension is confirmed, your doctor will perform additional tests to assess cardiovascular risk and check for organ damage. These typically include blood tests for cholesterol, blood sugar, and kidney function; urinalysis to check for protein or blood; an electrocardiogram (ECG) to detect heart abnormalities; and possibly additional tests like echocardiogram or kidney ultrasound if complications are suspected. This comprehensive evaluation helps determine treatment intensity and monitors for conditions that could complicate hypertension management.
What Lifestyle Changes Lower Blood Pressure?
The most effective lifestyle interventions are the DASH diet, sodium reduction to under 2,300 mg daily, regular aerobic exercise, weight loss if overweight, alcohol moderation, and stress management. These changes can reduce blood pressure by 5-20 mmHg and may allow some people to avoid or reduce medication.
The DASH (Dietary Approaches to Stop Hypertension) diet emphasizes fruits, vegetables, whole grains, lean proteins, and low-fat dairy while limiting saturated fat, cholesterol, and sweets. Studies show DASH can lower systolic blood pressure by 8-14 mmHg. Reducing sodium intake to below 2,300 mg daily (or ideally 1,500 mg for those with hypertension) can decrease blood pressure by 5-6 mmHg. Losing even 5-10 pounds if overweight can significantly impact blood pressure, with every pound lost potentially reducing systolic pressure by 1 mmHg.
Regular physical activity is powerfully effective for blood pressure control. Aim for at least 150 minutes of moderate aerobic exercise weekly (brisk walking, swimming, cycling) or 75 minutes of vigorous activity. Exercise can lower blood pressure by 5-8 mmHg. Limiting alcohol to no more than two drinks daily for men or one for women, managing stress through mindfulness or meditation, getting 7-9 hours of quality sleep, and quitting smoking all contribute to better blood pressure control. These lifestyle modifications work synergistically—combining several approaches produces greater benefits than any single change alone.
What Medications Treat High Blood Pressure?
First-line medications include thiazide diuretics, ACE inhibitors, ARBs, and calcium channel blockers. Your doctor selects medication based on your blood pressure level, other health conditions, and potential side effects. Many people need multiple medications to reach target blood pressure.
Thiazide diuretics like hydrochlorothiazide help your kidneys eliminate sodium and water, reducing blood volume. ACE inhibitors (like lisinopril) and ARBs (like losartan) relax blood vessels by blocking hormones that cause vessel narrowing. Calcium channel blockers (like amlodipine) prevent calcium from entering heart and blood vessel cells, causing vessels to relax. Beta-blockers (like metoprolol) reduce heart rate and the heart's workload. Each class has specific advantages: diuretics are inexpensive and effective, ACE inhibitors protect kidneys in diabetes, ARBs have fewer side effects than ACE inhibitors, and calcium channel blockers work well in African Americans and older adults.
Most people with Stage 2 hypertension need two medications from different classes to achieve blood pressure control. Combination pills that contain two medications improve convenience and compliance. Starting with lower doses and gradually increasing reduces side effects while achieving blood pressure goals. Common side effects vary by medication class: diuretics may cause increased urination and low potassium, ACE inhibitors can cause dry cough, ARBs rarely cause side effects, calcium channel blockers may cause ankle swelling, and beta-blockers can cause fatigue. Never stop blood pressure medication suddenly without consulting your doctor, as this can cause dangerous blood pressure spikes.
How Often Should I Monitor My Blood Pressure?
If you have hypertension, monitor blood pressure at home at least weekly, or daily when starting new treatment. Take readings at the same times each day, typically morning and evening before medications. Keep a log to share with your doctor at regular checkups every 3-6 months.
Home blood pressure monitoring provides valuable information that office readings alone cannot capture. Use a validated automatic upper-arm cuff monitor (not wrist or finger devices). Measure at the same times daily, ideally before taking medication and before breakfast in the morning, and again before dinner in the evening. Sit quietly for 5 minutes before measuring, don't talk during measurement, and take two or three readings one minute apart, then average them. Record all readings with date and time in a logbook or smartphone app.
Bring your home monitor to medical appointments occasionally to verify it's accurate compared to office equipment. Contact your doctor if readings are consistently higher than usual, if you experience symptoms like severe headache, vision changes, chest pain, or shortness of breath, or if systolic pressure exceeds 180 or diastolic exceeds 120. Regular monitoring helps detect 'white coat hypertension' and 'masked hypertension,' ensures treatments are working, improves medication compliance, and gives you greater involvement in managing your health. Studies show people who monitor blood pressure at home achieve better control than those who don't.
