Blood Pressure: Normal Ranges, Risk Factors and How to Monitor It

High blood pressure, or hypertension, remains one of the most common chronic conditions in the United States. The Centers for Disease Control and Prevention (CDC) reports that about 48.1% of U.S. adults, or roughly 119.9 million people, have high blood pressure, based on survey data collected from 2017 through March 2020. The CDC also says hypertension was a primary or contributing cause of 680,179 deaths in the United States in 2024.

What the numbers mean

A blood pressure reading has two numbers. The systolic number, listed first, measures the pressure inside the arteries when the heart beats. The diastolic number, listed second, measures the pressure when the heart rests between beats, according to the U.S. National Library of Medicine's MedlinePlus.

Under the categories used by MedlinePlus and the American College of Cardiology/American Heart Association framework, blood pressure is grouped into five bands based on the higher of the two numbers.

A reading above 180/120 mm Hg requires prompt medical attention. The 2025 AHA/ACC hypertension guideline, summarized in a journal article hosted by the National Institutes of Health's PMC database, replaces the older term 'hypertensive urgency' with 'severe hypertension' to describe markedly elevated readings in patients without acute damage to organs such as the kidneys or heart.

Risk factors

The CDC groups the main drivers of high blood pressure into factors that can be changed and factors that cannot.

• Unhealthy diet, including high sodium and low potassium intake
• Physical inactivity
• Excessive alcohol use — the CDC cites a limit of one drink a day for women and two for men
• Tobacco use
• Obesity
• Diabetes — the CDC states about 6 in 10 people with diabetes also have high blood pressure
• Pregnancy, which can trigger blood pressure increases
• Age, since risk rises as people get older
• Family history and genetics
• Race and ethnicity — the CDC says high blood pressure is more common among Black adults than among White, Hispanic, Asian, Pacific Islander, American Indian or Alaska Native adults, and that it tends to develop earlier in life for Black Americans

How to monitor blood pressure accurately

MedlinePlus recommends that everyone age 3 and older have their blood pressure checked at least once a year, with more frequent checks for people 40 or older, people with obesity, or those with a family history of heart disease or hypertension. For home monitoring, MedlinePlus outlines the following steps.

1. Use an upper-arm digital monitor rather than a wrist or finger device, and make sure the cuff fits snugly around the upper arm, just above the elbow.
2. Avoid exercise, caffeine, food, alcohol or tobacco for at least 30 minutes before measuring, and go to the bathroom first.
3. Sit quietly and rest for about five minutes before taking a reading.
4. Sit with your back supported, feet flat on the floor and legs uncrossed, resting your arm on a surface so it is level with your heart.
5. For home monitoring, take your blood pressure at the same time of day each time.
6. Record each reading and report the results to a healthcare provider.

Why the 2025 guideline update matters

The 2025 AHA/ACC guideline, described in the PMC-hosted summary, keeps a treatment goal of below 130/80 mm Hg for most adults being treated for hypertension, while encouraging a target below 120/80 mm Hg where it can be reached safely. For Stage 2 hypertension — 140/90 mm Hg or higher — the guideline now recommends starting treatment with two blood-pressure-lowering medications at once, preferably combined into a single pill to help patients stay on treatment.

The guideline also elevates the role of out-of-office measurement. Home blood pressure monitoring and ambulatory monitoring (a wearable device that records readings over 24 hours) are now positioned as central tools, alongside office readings, for identifying 'white-coat hypertension' (high readings only in clinical settings) and 'masked hypertension' (normal readings in clinic but high readings elsewhere), according to the PMC summary. The guideline also introduces the PREVENT risk calculator, a tool that estimates a person's 10-year and 30-year cardiovascular disease risk for adults aged 30 to 79, incorporating factors such as kidney function alongside traditional measures.

Despite available treatments, CDC data show only about 1 in 4 U.S. adults with hypertension — roughly 22.5%, or 27 million people — have the condition effectively managed. The agency also estimates that high blood pressure was linked to about $219 billion in costs in the United States in 2019.