High blood pressure or hypertension is known as a silent killer. This is because it's a serious health problem, but often doesn't cause symptoms. Many people don't know they have it until it leads to other health problems.

Normal blood pressure is less than 120/80 mmHg. If you're above this level for several readings over time, you'll be diagnosed with high blood pressure. Healthy changes can help you lower your blood pressure. But after you're diagnosed, you'll need to manage it for the rest of your life.

Your heart pumps blood into the blood vessels that carry it through your body. With each heartbeat the heart pushes blood through blood vessels called arteries. Blood pressure is a measure of how hard the blood pushes against the walls of the arteries as it flows.

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

High blood pressure means that the blood is pushing too hard against artery walls. This damages the walls. The walls form scar tissue as they heal. But the scar tissue makes the arteries stiff and weak. A fatty substance called plaque sticks to the scar tissue. This makes arteries narrower and harder.

High blood pressure:

• Causes your heart to work harder to get blood around your body.
• Raises your risk for heart attack, heart failure, and stroke.
• Can lead to kidney disease and blindness.

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. That's called systolic. The bottom number is the pressure of blood against artery walls between heartbeats. That's called diastolic.

Blood pressure may be:

• Normal: Systolic is lower than 120 and diastolic is lower than 80.
• Elevated: Systolic is 120-129 and diastolic is less than 80.
• High, Stage 1: Systolic is 130-139 or diastolic is 80-89.
• High, Stage 2: Systolic is 140 or higher or diastolic is 90 or higher.

For most people with high blood pressure, keeping readings under 130/80 mmHg may help prevent health problems. Talk with your doctor. Find out what your blood pressure goals should be. Tell them what concerns you have about your readings.

If your blood pressure is high, work with your doctor to lower it. Lifestyle changes and possibly medicines may help.

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). It includes a lot of fruits and vegetables, low-fat or nonfat dairy foods, whole grains, and other foods high in fiber and low in fat. This plan also includes more dietary potassium. This can help lower blood pressure.
• Cut sodium. Eating less sodium reduces fluid retention. This means that your body holds on to too much water. Having too much salt increases blood volume and blood pressure. The American Heart Association says the ideal limit is no more than 1,500 mg of sodium a day, especially if you have high blood pressure. But because people in the U.S. eat so much salt, they say cutting back to even 2,300 mg a day can help. Having only 1,000 mg of sodium a day can help your blood pressure and heart.
• Get to or stay at a weight that's healthy for you. 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.
• Don't smoke. Smoking raises blood pressure. And it damages blood vessels.
• Limit alcohol. For some people, it's best to avoid alcohol completely. Drinking too much alcohol can raise blood pressure.
• Control stress. Stress makes your heart work harder and beat faster. Managing stress in a healthy way helps you control your blood pressure.

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