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What is High Blood Pressure?

This condition is called the “silent killer” because it often has no symptoms.

By Ginny Greene, Contributing Editor

At each doctor visit, one of the first things the nurse does is check your blood pressure. Do you know why this is important?

Why it matters
Blood pressure measures the force of blood pressing against your arteries as it travels through your body. If that pressure is too high, it puts you at risk for heart disease, stroke, kidney failure and other complications. High blood pressure is referred to as the "silent killer" because it often has no symptoms.

High blood pressure, or hypertension, is largely preventable or treatable in most people. Bringing your numbers down will lower your risk for disease and premature death.

Blood pressure is measured in millimeters of mercury (mm Hg). Readings are recorded as a fraction. For example: 120/80 mm Hg is "120 over 80."

  • Systolic pressure is the top number. This is the pressure on your arteries when your heart beats.
  • Diastolic pressure is the bottom number. This is the pressure when your heart is resting between beats.

Blood pressure readings vary during the day, depending on your activity level and other factors such as whether you are nervous or excited. Blood pressure is often lower when you sleep and higher when you exercise. High blood pressure is diagnosed if you have persistently elevated blood pressure readings.

How is it treated?
In some people, making certain lifestyle changes can bring down blood pressure. In others, medicine may also be prescribed along with healthy changes to your habits and activities. You and your doctor should discuss the best ways to bring your blood pressure down. Your goals may include:

  • Reaching or maintaining a healthy weight. 
  • Eating healthy foods. Studies have shown that some specific eating plans, including the Dietary Approaches to Stop Hypertension (DASH) diet, may help control high blood pressure. Dietary patterns that have been shown to help are rich -in vegetables, fruits and whole grains. Sugar-sweetened drinks, sweets and foods high in saturated and total fat and cholesterol such as red meats are limited. The diet recommends low fat dairy, fish, poultry, beans and nuts, and non-topical vegetable oils. The DASH diet is high in potassium, which also can help reduce blood pressure.
  • Limiting sodium (salt) intake. Experts recommend limiting sodium intake to no more than 2,400 mg per day. If you can lower your sodium intake to 1,500 mg a day, you may lower your blood pressure even more. Just dropping your intake by 1,000 mg a day — even if you’re not yet at the desired level — can lower your blood pressure.
  • Getting physically active, with your doctor's approval and exercise recommendations.
  • Limiting alcohol. If you choose to drink, limit it to two drinks a day for men or one drink a day for women.
  • Quitting smoking. Smoking raises your risk for heart disease and other serious medical problems.

Changes to your lifestyle may not be enough to control your high blood pressure. Often, people need one or more medicines in addition to lifestyle modifications. Be sure to take any medication as your doctor prescribes.


James PA, Oparil S, Carter BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the eighth joint national committee (JNC 8). JAMA. 2014;311(5):507-520. Accessed: October 19, 2015.
National Heart, Lung, and Blood Institute. What is high blood pressure? Accessed: October 19, 2015.
Eckel RH, Jakicic JM, Ard JD, et al. 2013 AHA/ACC guideline on lifestyle management to reduce cardiovascular risk. Circulation. 2013; doi: 10.1161/01.cir.0000437740.48606.d1. Accessed: October 19, 2015.

Last Updated: October 20, 2015