Overview
Blood pressure (BP) refers to the force that blood exerts on the blood vessels as it circulates through your body. It plays a central role in heart health: cardiovascular disease risk is strongly associated with an increase in blood pressure, even when BP is within normal range.[1][2]
As your blood pressure increases, it strains your blood vessels and heart. If it remains too high (hypertension), this can increase your risk for heart attacks, strokes, vascular diseases, eye damage, kidney disease, and more.
As your BP drops, the pressure on the blood vessel walls decreases. If it remains too low (hypotension), you may not get enough oxygen to critical parts of your body, such as the brain and heart.
There are multiple risk factors that can contribute to the development of high blood pressure.
- Age: As you age, blood pressure tends to go up.
- Family history: Nearly 100 genetic variations have been associated with high blood pressure. While a family history of high BP raises your risk, the exact pattern of genetic inheritance is not known.
- Lifestyle: Too much sodium (salt), insufficient potassium, not enough exercise, excessive alcohol intake, and smoking can all contribute to high blood pressure.
- Race/ethnicity: Black adults experience high blood pressure more frequently.
- Sex: Prior to age 55, males are more likely to develop high blood pressure. After 55, females are more likely to develop it.
- Weight: People who carry too much fat have an increased risk of high blood pressure.
How are blood pressure levels assessed?
Blood pressure is most commonly measured using a blood pressure monitor or gauge (where a cuff is placed around your upper arm). It can be measured either in a single sitting or via ambulatory blood pressure monitoring (ABPM) over 24 hours with a leave-on cuff. The latter is likely to be more accurate and result in fewer anomalous measurements since blood pressure can naturally fluctuate throughout the day.
Blood pressure is reported in two numbers; e.g., 120/80 mmHg (millimeters of mercury — a unit of pressure).
- The first number, systolic blood pressure, tells us how much pressure your blood is exerting against the arterial walls when your heart contracts.
- The second number, diastolic blood pressure, signifies how much pressure your blood is exerting when the heart is relaxed and refilling with blood.
Blood pressure measurements are generally divided into the five categories below.
| CATEGORY | SYSTOLIC | DIASTOLIC |
|---|---|---|
| Low blood pressure |
≤90
|
≤65
|
| Normal blood pressure |
<120
|
<80
|
| Elevated blood pressure |
120–129
|
<80
|
| Stage 1 hypertension |
130–139
|
80–89
|
| Stage 2 hypertension |
≥140
|
≥90
|
Adapted from Whelton et al. Hypertension. 2018.[3]
In adults 65 or older, a blood pressure goal of 125–130 systolic and <80 diastolic is recommended.