Hypertension, or high blood pressure, is called "the silent killer" for a good reason: You can have it and not even know it. If you have hypertension, you need to know, so you can control it. If you don't, you increase your risk for serious illness.

Hypertension is the medical term for high blood pressure. Blood pressure is the force at which blood flows through the large blood vessels from the heart. Blood pressure is most frequently measured with an inflatable cuff put on the upper arm. The cuff is attached to a device that measures the pressure in the arteries in your arm. The cuff is inflated, squeezing the blood vessels so they don’t let as much blood through. The air is then let out of the cuff. In a moment or so, blood starts to flow normally again and the device measures the pressure in the blood vessels when that happens. These two measurements are called a blood pressure reading.

Blood pressure readings are split into two numbers. An example of a blood pressure reading is 110/70. The top number is the systolic pressure. This is the pressure caused when the heart contracts. A normal systolic reading is less than 120. The bottom number is the diastolic pressure. This is the pressure that remains when the heart relaxes. A normal diastolic reading is less than 80.

Hypertension is diagnosed when the systolic reading is 140 or higher, or the diastolic reading is 90 or higher. Usually, high readings have to be seen on several different days to give an accurate diagnosis. The higher the readings are, the more severe the hypertension is. A systolic pressure of 120 to 139 or a diastolic pressure of 80 to 89 is known as prehypertension.

Why Hypertension Matters

Hypertension is the single greatest risk factor for heart disease. Heart disease is the leading cause of death in the United States. Hypertension is called a silent killer because it often has no symptoms. It causes the heart to work harder. Over time, this causes the heart to weaken and can lead to heart failure. Hypertension can also damage your blood vessels and other parts of the body. It can lead to stroke, kidney failure, and blindness.

Risk Factors for Hypertension

The risk for having hypertension increases as you get older. About 1 in 3 adults in the United States has hypertension. And nearly 30 percent more have prehypertension.

In about 90 to 95 percent of people with hypertension, there is no known cause.

Others may have a condition such as kidney disease, hormone problems, or another illness that causes hypertension.

Factors that are linked to hypertension include a family history of hypertension. Race, gender, and age are factors. Some people are sensitive to sodium, and this is linked to hypertension.

Other important risk factors include health conditions such as diabetes, gout, kidney disease, and high cholesterol. Lifestyle issues such as smoking, excess weight, and lack of exercise are risk factors.

Pregnancy and use of oral contraceptives are linked to hypertension. And some medications,  such as herbal supplements, over-the-counter prescription, and street drugs may cause hypertension.


If you are diagnosed with hypertension, your eyes or kidneys may be checked for damage. The retinas of the eye may be examined. Laboratory tests may be done to check for kidney function. Your heart may be tested with an electrocardiogram, also known as an ECG. Blood tests may be done to check cholesterol and glucose levels. More testing may be done as needed.

If it's found, the cause of your hypertension will be treated.

But most of the time, no cause is found. Making lifestyle changes is the first step in treating hypertension.

Eating healthy foods, getting regular exercise, stopping smoking, and drinking less alcohol can help lower blood pressure.

Eating less saturated fat can lower blood pressure and may help with weight loss. Eating less sodium can lower the amount of fluid that stays in the bloodstream. This can lower blood pressure. Alcohol can raise your blood pressure, so drink less. Caffeine is a stimulant that affects the heart, so drinking less coffee, and fewer sodas or other caffeinated beverages will help.

Exercise helps lower body weight and body fat, control blood pressure and reduce stress. It also strengthens the heart. And in people who have diabetes, exercise can help control blood sugar. If you haven’t exercised in a while, talk with your healthcare provider before starting a new exercise program.

Quitting smoking is one of the most important things you can do for your blood pressure and your overall health. Quitting now can lower your blood pressure and help prevent more damage to your arteries, heart, and lungs.

If lifestyle changes aren’t enough to lower your blood pressure, you may be given medication. Different people have different responses to blood pressure medications. More than one type may be needed. And your medication may be changed within the first weeks or months of treatment to see what works best. Your health care provider will tailor your medication to your needs.

What To Do

Stop smoking. Keep track of your blood pressure. Learn to take your own blood pressure at home with a blood pressure machine. Use a diary to keep track of your blood pressure.  Relax and take steps to manage stress. Try meditation, biofeedback, psychotherapy, and exercise to help lower your stress levels and blood pressure. If you are thinking about having a baby and you have hypertension, talk to your healthcare provider. He or she can advise you on steps to take to control your blood pressure before and during pregnancy.

When to call your health care provider

Call your healthcare provider if you have changes in urination or unusual swelling. Call if your medications are causing side effects, including nausea, vomiting, diarrhea, persistent cough, or symptoms such as lightheadedness, dehydration or dizziness. Do not stop taking blood pressure medicine without talking to your provider. Call 911 and seek emergency care if you notice chest pain, shortness of breath or changes in vision, ability to speak, swallow, walk, or use your limbs.

What We Have Learned

  1. Hypertension is the single greatest risk factor for heart disease. True or False?
    The answer is True. High blood pressure causes the heart to work harder. Over time, this causes the heart to weaken and can lead to heart failure.
  2. Hypertension is known as a silent killer. True or False?
    The answer is True. That’s because hypertension rarely has symptoms.
  3. Hypertension is often treated with lifestyle changes such as diet, exercise, and quitting smoking. True or False?
    The answer is True. If lifestyle changes aren’t enough to lower your blood pressure, you may be given medication.