What Is High Blood Pressure?

High blood pressure (hypertension) is known as the silent killer. This is because most of the time it doesn’t cause symptoms. In fact, many people don’t know they have it until other health problems develop.

High blood pressure is diagnosed when blood pressure readings taken at several different times show levels higher than 130/80 mmHg. Healthy changes can help lower blood pressure. But once you have high blood pressure, you'll need to manage it for the rest of your life.

Understanding blood pressure

The circulatory system is made up of the heart and blood vessels that carry blood through the body. Your heart is the pump for this system. With each heartbeat (contraction), the heart sends blood out through large blood vessels called arteries. Blood pressure is a measure of how hard the moving blood pushes against the walls of the arteries.

High blood pressure can harm your health

In a healthy artery, the blood moves smoothly and puts normal pressure on its walls.

Cross section of artery with arrows showing normal blood pressure on inside walls. Cross section of artery with arrows showing high blood pressure on inside walls. Cross section of artery showing damaged lining and plaque buildup.

High blood pressure results from blood pushing too hard against artery walls. This damages the walls, which form scar tissue as they heal. The scar tissue makes the arteries stiff and weak. Plaque also sticks to the scar tissue, making arteries narrower and harder..

High blood pressure:

Causes your heart to work harder to get blood out to the rest of your body
Raises your risk for heart attack, heart failure, and stroke
Can lead to kidney disease and blindness

Measuring blood pressure

It's important to know your blood pressure numbers. A blood pressure reading is given as two numbers, such as 120/70. The top number is the pressure of blood against the artery walls during a heartbeat (systolic). The bottom number is the pressure of blood against artery walls between heartbeats (diastolic).

Blood pressure categories are:

Normal: lower than 120/lower than 80 mmHg
Elevated (prehypertensive): 120-139/80-89 mmHg
High, Stage 1: 130-139/80-89 mmHg
High, Stage 2: 140/90 mmHg and higher

For most people with high blood pressure, keeping readings lower than 130/80 mmHg may help prevent health problems. Talk with your healthcare provider to find out what your blood pressure goals should be. Bring up any questions or concerns you have about your readings.

Controlling blood pressure

If your blood pressure is too high, work with your healthcare provider to make a plan for lowering it. They may prescribe medicine to help control your blood pressure if lifestyle changes aren't enough.

Below are changes you can make to help lower your blood pressure:

Choose heart-healthy foods. Ask your provider about the Dietary Approaches to Stop Hypertension (DASH) eating plan. DASH limits sodium (salt) and offers lots of fruits and vegetables, low-fat or nonfat dairy products, whole grains, and other foods high in fiber and low in fat. This plan also includes an increased amount of potassium, which can help lower blood pressure.
Reduce sodium. Eating less sodium reduces fluid retention. Fluid retention caused by too much salt increases blood volume and blood pressure. The American Heart Association (AHA) says to have no more than 1,500 mg sodium a day. But because Americans eat so much salt, the AHA says cutting back to even 2,300 mg a day offers benefits.
Stay at a healthy weight. Being overweight makes you more likely to have high blood pressure. Losing excess weight helps lower blood pressure.
Exercise regularly. Daily exercise helps your heart and blood vessels work better and stay healthier. It can help lower your blood pressure.
Do not smoke. Smoking increases blood pressure and damages blood vessels.
Limit alcohol. Drinking too much alcohol can raise blood pressure. Men should have no more than 2 drinks a day. Women should have no more than 1 a day. A drink is equal to 1 beer, a small glass of wine, or a shot of liquor.
Control stress. Stress makes your heart work harder and beat faster. Managing stress in a healthy way helps you control your blood pressure.

Facts about high blood pressure

Feeling OK doesn't mean your blood pressure is under control. Likewise, feeling bad doesn’t mean it’s out of control. The only way to know for sure is to check your pressure regularly.
Medicine is only one part of controlling high blood pressure. You also need to manage your weight, get regular exercise, and adjust your eating habits.
High blood pressure is often a lifelong health problem. But it can be controlled with lifestyle changes and medicine.
Hypertension isn't the same as stress. Although stress may be a factor in high blood pressure, it’s only one part of the story.
Blood pressure medicines need to be taken every day. Stopping suddenly may cause a dangerous increase in pressure.