Your blood pressure is an important part of your overall health. But what is it? 

What is blood pressure?

Blood pressure is the force of the blood pushing against the walls of your blood vessels. If it is too high, it can put a strain on your heart and blood vessels and can lead to increased risk of heart disease and stroke.

Your blood pressure is measured using a device called a sphygmomanometer – the cuff that goes around your arm. The measurement then indicates a unit of pressure known as millimeters of mercury (or mm Hg), written as two numbers. 

The top number, known as the systolic pressure, measures the force of the blood against the artery walls when the heart contracts to pump blood out. The heart is working its hardest at that point.

The bottom number, known as the diastolic pressure, measures the force of the blood when the heart is “resting” in between contractions. That number is lower.

Doctors use standard guidelines to determine if your blood pressure falls into a range known as “normal.” If your blood pressure is consistently above the normal range, it is known as hypertension, or high blood pressure. 

What are the dangers of high blood pressure?

High blood pressure, or hypertension, is known as the “silent killer.” This means it often does not have any noticeable symptoms (unless severely elevated) and can go untreated for a long time, which can lead to major health risks. 

Prolonged, untreated high blood pressure can lead to:

  • heart attack
  • stroke
  • congestive heart failure
  • visual disturbances including blindness
  • kidney disease 

High blood pressure along with diabetes represent the top two causes of kidney failure requiring dialysis in the United States. 

Blood pressure ranges and guidelines

The American Heart Association and the American College of Cardiology revised the blood pressure classification guidelines in November 2017. Recognizing the major health risks of even small increases in blood pressure over the long term, the new guidelines have a lower cutoff for the classification of high blood pressure. 

The blood pressure guidelines are:
Normal: less than 120/80 mm Hg
Elevated: systolic between 120-129 and diastolic less than 80
Stage 1 hypertension: systolic between 130-139 or diastolic between 80-89
Stage 2 hypertension: systolic at least 140 or diastolic at least 90 mm Hg
Hypertensive crisis: systolic over 180 and/or diastolic over 120, with patients needing prompt changes in medication if there are no other indications of problems, or immediate hospitalization if there are signs of organ damage.

What can I do to lower my blood pressure?

There are lifestyle changes we can all make to help control blood pressure. 

  • Follow the Dietary Approaches to Stop Hypertension, or DASH diet. This includes fruits, vegetables, whole grains, and low-fat dairy products with reduced saturated and total fat.
  • Increase your physical activity. Add 150 minutes of moderate intensity aerobic exercise, such as a brisk walk, each week. Also, include strength training three days a week. Not only can this help reduce or control your blood pressure, but it can also help with weight management and stress relief. In overweight individuals, a weight loss of even five to ten percent has been shown to reduce blood pressure.
  • Limit your sodium to no more than 2000 milligrams each day, and ideally less than 1500 milligrams in keeping with the American Heart Association recommendations. The average American takes in far more than this - approximately 3400 milligrams of sodium each day. For most people, reaching these goals will require making more food at home and checking labels when purchasing premade meals or ordering takeout. Experiment with spices instead of adding salt to your food. Please talk to your doctor before considering salt substitutes.
  • Limit your alcohol. It is recommended that men have no more than two drinks per day and women have no more than one to help control blood pressure.
  • Manage your stress. Because stress can have a major impact on our bodies, it is important to find effective coping techniques that work for you. 
  • If you smoke, quit. Quitting smoking can have a huge impact on your health regardless of how long you have been smoking. It is never too late.

These are some of the most important ways you can support a normal blood pressure and an overall healthy life. 

Blood pressure medication

For some, even a healthy lifestyle is not enough to maintain a safe blood pressure. When lifestyle modifications do not lower blood pressure to better levels, medication can be prescribed.

Your doctor will prescribe an appropriate medication based on your blood pressure category, taking into consideration other co-existing medical conditions and factors such as age. Sometimes, more than one medication is necessary. Some patients may need more frequent monitoring. Anyone with a blood pressure reading in the “crisis” stage needs immediate medical attention.

Be good to yourself and try to keep your blood pressure controlled by living a healthy lifestyle. If this is not enough, there are several well-tolerated and effective medication options for those patients who need them as well. Your heart will thank you!

If you have high blood pressure, talk with your doctor or see a cardiologist who can help you keep yours under control. 

Matthew A. Kluge, MD

Matthew A. Kluge, MD

Matthew Kluge, MD, MA, is a cardiologist with the Lifespan Cardiovascular Institute. He earned both his master of arts in medical sciences and medical degree at Boston University and completed his residency in internal medicine at Boston University Medical Center.