Hypertension (High Blood Pressure): Causes, Risks, Diagnosis & Treatment Guide

Blood pressure reflects two forces: the volume of blood moving through your vessels and the resistance the heart must overcome to pump that blood.

Hypertension, or high blood pressure, occurs when the force exerted on artery walls is consistently elevated. This guide explains what hypertension is, its common risk factors, how it’s diagnosed, and the most effective ways to manage it.

How Blood Pressure Is Measured

A cuff placed around the upper arm inflates to temporarily stop blood flow. As the cuff deflates, two numbers are recorded:

• Systolic pressure (top number): pressure in the arteries when the heart contracts.
• Diastolic pressure (bottom number): pressure in the arteries between heartbeats.

Blood‑Pressure Categories (American Heart Association, 2017)

• Normal: <120 mm Hg systolic and <80 mm Hg diastolic (written 120/80).
• Elevated: 120‑129 mm Hg systolic and <80 mm Hg diastolic. Lifestyle changes are usually recommended.
• Stage 1 hypertension: 130‑139 mm Hg systolic or 80‑89 mm Hg diastolic.
• Stage 2 hypertension: ≥140 mm Hg systolic or ≥90 mm Hg diastolic.
• Hypertensive crisis: >180 mm Hg systolic or >120 mm Hg diastolic. Immediate medical attention is required, especially if accompanied by chest pain, severe headache, shortness of breath, or visual changes.

Why Blood Pressure Increases

Narrowed arteries create greater resistance to blood flow, forcing the heart to work harder. Over time, this heightened pressure can damage the heart, brain, eyes, and kidneys, leading to heart disease, stroke, and kidney failure.

How Common Is Hypertension?

Since the 2017 guideline update, nearly 50 % of U.S. adults meet the criteria for high blood pressure, according to the American Heart Association.

Symptoms — or Lack Thereof

Hypertension often develops silently over years. Most people feel fine until organ damage occurs. When blood pressure reaches a crisis level, symptoms may include:

• Headache
• Nausea or vomiting
• Blurred vision
• Chest or back pain
• Difficulty breathing

Essential (Primary) Hypertension

About 90‑95 % of cases are “essential” hypertension, where no single cause is identifiable. Contributing factors include:

• Genetics: Family history raises risk.
• Age: Risk climbs after age 65.
• Race: Black adults in the U.S. experience higher rates, reflecting genetic, cultural, and socioeconomic influences.
• Obesity: Excess weight strains the cardiovascular system.
• Alcohol: Even one drink per day modestly increases risk; higher intake magnifies it.
• Sedentary lifestyle: Physical inactivity is linked to higher blood pressure.
• Diabetes or metabolic syndrome: These conditions often coexist with hypertension.
• High sodium intake: Consuming more than 5 g of salt daily is strongly associated with elevated pressure.

Secondary Hypertension

Secondary hypertension results from an identifiable medical condition or medication and often appears abruptly. Common causes include kidney disease, endocrine disorders (e.g., hyperaldosteronism), certain drugs (e.g., oral contraceptives, decongestants), and sleep apnea.

Diagnosing Hypertension

Diagnosis is based on repeated, accurate readings taken on different days. A single elevated measurement is insufficient because factors such as “white‑coat syndrome” or normal daily fluctuations can affect results.

When hypertension is confirmed, clinicians may order additional tests to rule out secondary causes, including blood tests, urinalysis, kidney imaging, and electrocardiograms.

Treatment Overview

Management combines lifestyle modification with medication when needed. Early, consistent control reduces the risk of heart attack, stroke, and organ damage.

Lifestyle Strategies

• Adopt a DASH‑style diet rich in fruits, vegetables, whole grains, and low‑fat dairy while limiting sodium (<1,500 mg/day).
• Engage in at least 150 minutes of moderate‑intensity aerobic activity weekly.
• Maintain a healthy weight (BMI < 25 kg/m²).
• Limit alcohol to ≤2 drinks/day for men and ≤1 drink/day for women.
• Quit smoking and manage stress through relaxation techniques or counseling.

Medications

When lifestyle changes are insufficient, doctors prescribe one or more of the following classes, often tailoring therapy through trial and error:

• ACE inhibitors (e.g., lisinopril)
• Angiotensin II receptor blockers (ARBs) (e.g., losartan)
• Thiazide diuretics (e.g., hydrochlorothiazide)
• Calcium‑channel blockers (e.g., amlodipine)
• Beta‑blockers (e.g., metoprolol)

For secondary hypertension, treating the underlying condition—such as adjusting a problematic medication or managing sleep apnea—can normalize blood pressure, sometimes in combination with the drugs listed above.

Monitoring and Follow‑Up

Regular home monitoring helps track progress and detect “white‑coat” effects. Most clinicians recommend checking blood pressure at the same time each day, using a cuff that fits properly.

Children and adolescents have age‑specific reference ranges; discuss appropriate targets with your pediatrician.

Potential Complications

Uncontrolled hypertension can:

• Harden and narrow arteries (atherosclerosis)
• Promote plaque buildup, increasing heart‑attack risk
• Damage kidneys, leading to chronic kidney disease
• Cause retinal injury and vision loss
• Increase the likelihood of aneurysms and heart failure

Because the condition is often silent, routine checks are the most reliable way to catch it early and prevent these outcomes.