Know your numbers: Blood pressure

By Mayo Clinic staff

Knowing and understanding key heart numbers — blood pressure, cholesterol and heart rate, along with your family history — allow you and your health care team to determine your risk for developing heart and cardiovascular disease. Knowing your risk is critical to preventing heart disease and for taking steps to improve your overall heart health.

Here is information about one of the most dangerous and sneakiest health conditions: blood pressure.

What is blood pressure?

Blood pressure is a measure of how hard your blood pushes against your arteries as it moves through your body. High blood pressure occurs when your blood pressure, the force of your blood against the walls of your blood vessels, is consistently too high. High blood pressure is harmful because it makes the heart work harder and less efficiently.

Why blood pressure matters

High blood pressure can cause significant damage to your eyes, kidneys, brain and blood vessels. Left untreated, it can lead to kidney failure or vision loss. High blood pressure also can affect your ability to think, remember and learn. There's even a type of dementia — vascular dementia — caused by high blood pressure.

High blood pressure is one of the most dangerous health conditions because of how sneaky it can be. You can have high blood pressure for years without experiencing any symptoms. Even without symptoms, damage to your heart can still occur. Fortunately, high blood pressure can be easily detected. And once you know you have high blood pressure, you can work with your health care provider to control it.

How is blood pressure measured?

Blood pressure is traditionally measured using an inflatable cuff around your arm. The cuff is inflated, and the cuff gently tightens on your arm. The air in the cuff is slowly released and a small gauge measures your blood pressure.

Your blood pressure is recorded as two numbers:

• Systolic blood pressure (the first number) — This number indicates how much pressure your blood is pushing against your artery walls when the heart beats.
• Diastolic blood pressure (the second number) — This number indicates how much pressure your blood is pushing against your artery walls while the heart is resting between beats.

Blood pressure is measured using millimeters of mercury, or mm Hg. Mercury was used in the first accurate pressure gauges, and it is still used today as the standard unit for measuring pressure.

What is considered normal?

Your blood pressure reading will fall into one of these four categories:

• Normal — Blood pressure readings of less than 120/80 mm Hg are considered in the normal range.
• Elevated — Readings consistently ranging from 120–129 systolic and less than 80 mm Hg diastolic are considered elevated.
• Hypertension stage 1 — This stage is characterized by readings ranging from 130–139 systolic or 80–89 mm Hg diastolic.
• Hypertension stage 2 — This stage is characterized by readings consistently ranging at 140/90 mm Hg or higher.

What you can do

• Quit smoking. Tobacco temporarily raises blood pressure and can damage artery walls over time. Quitting smoking is one of the best things you can do for your health.
• Follow the DASH diet. The Dietary Approaches to Stop Hypertension, or DASH, diet includes whole grains, fruits, vegetables and low-fat dairy products. The diet encourages limiting saturated fat and foods containing high cholesterol. Following the DASH diet can lower your blood pressure by up to 11 mm Hg if you have high blood pressure.
• Get active. Regular physical fitness ― about 30 minutes per day or 150 minutes per week ― can lower your blood pressure by about 5 to 8 mm Hg.
• Limit alcohol. By drinking alcohol in moderation ― generally one drink a day for women or two a day for men ― you can potentially lower your blood pressure by about 4 mm Hg. One drink equals 12 ounces of beer, 5 ounces of wine or 1.5 ounces of 80 proof liquor.
• Skimp on the salt. In general, limit sodium to 2,300 milligrams per day or less. However, a lower sodium intake ― 1,500 mg a day or less ― is ideal for most adults. Download an infographic about salt.

Know your numbers

It's time to know your blood pressure numbers. Adults 40 and older or anyone with risk factors should have their blood pressure checked by a health care provider once a year. Younger people without risk factors should be checked at least every two years. Download an infographic about high blood pressure.

Visit Classes & Events to find a blood pressure screening near you.