High Blood Pressure

Symptoms and Diagnosis

High blood pressure is often called the "silent killer" because you can have it for years without knowing it. The only way to find out if you have high blood pressure is to have your blood pressure measured.


When blood pressure stays high over time, it can damage the body and cause complications. Here are some of the common complications, along with their signs and symptoms.

  • Aneurysms. These occur when an abnormal bulge forms in the wall of an artery. Aneurysms develop and grow for years without causing signs or symptoms until they rupture, grow large enough to press on nearby body parts, or block blood flow. The signs and symptoms that develop depend on the location of the aneurysm.
  • Chronic Kidney Disease. This disease occurs when blood vessels narrow in the kidneys, possibly causing kidney failure.
  • Cognitive Changes Research shows that over time, higher blood pressure numbers can lead to cognitive changes. Signs and symptoms include memory loss, difficulty finding words, and losing focus during conversations.
  • Eye Damage. This condition occurs when blood vessels in the eyes burst or bleed. Signs and symptoms include vision changes or blindness.
  • Heart Attack. This occurs when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart doesn’t get oxygen. The most common warning symptoms of a heart attack are chest pain or discomfort, upper body discomfort, and shortness of breath.
  • Heart Failure. This condition occurs when the heart can’t pump enough blood to meet the body’s needs. Common signs and symptoms of heart failure include shortness of breath or trouble breathing; feeling tired; and swelling in the ankles, feet, legs, abdomen, and veins in the neck.
  • Peripheral Arterial Disease. This is a disease in which plaque builds up in leg arteries and affects blood flow in the legs. When people have symptoms, the most common are pain, cramping, numbness, aching, or heaviness in the legs, feet, and buttocks after walking or climbing stairs.
  • Stroke. A stroke occurs when the flow of oxygen-rich blood to a portion of the brain is blocked. The symptoms of a stroke include sudden onset of weakness; paralysis or numbness of the face, arms, or legs; trouble speaking or understanding speech; and trouble seeing.

How Blood Pressure Is Checked

Your health care provider usually takes 2–3 readings at several medical appointments to diagnose high blood pressure. Based on the results of your blood pressure test, your health care provider will diagnose prehypertension or high blood pressure if your systolic or diastolic readings are consistently higher than 120/80 mmHg.

Once your health care provider determines the severity of your blood pressure, he or she can order additional tests to determine if your blood pressure is due to other conditions or medicines or if you have primary high blood pressure. Health care providers can use this information to develop your treatment plan.

Some people have “white coat hypertension.” This happens when blood pressure readings are only high when taken in a health care provider’s office compared with readings taken in any other location. Researchers believe stress, which can occur during the medical appointment, causes white coat hypertension.

Preparing for the Test

A blood pressure test is easy and painless and can be done in a health care provider’s office or clinic. To prepare for the test

  • don’t drink coffee or smoke cigarettes for 30 minutes prior to the test
  • go to the bathroom before the test. A full bladder can change the reading
  • sit for 5 minutes before the test.

To track blood pressure readings over a period of time, the health care provider may ask you to come into the office on different days and at different times to take your blood pressure. The health care provider also may ask you to check readings at home or at other locations that have blood pressure equipment and to keep a written log of all your results.

Whenever you have an appointment with the health care provider, be sure to bring your log of blood pressure readings. Ask the doctor or nurse to tell you your blood pressure reading in numbers and to explain what the numbers mean. Write down your numbers or ask the doctor or nurse to write them down for you.

Write Down Your Readings

Ask the doctor or nurse to tell you your blood pressure reading in numbers and to explain what the numbers mean. Write down your numbers or ask the doctor or nurse to write them down for you. (The wallet card on the right can be printed out and used to record your blood pressure numbers.)

Checking Your Own Blood Pressure

You can also check your blood pressure at home with a home blood pressure measurement device or monitor. It is important that the blood pressure cuff fits you properly and that you understand how to use the monitor. A cuff that is too small, for example, can give you a reading that is higher than your actual blood pressure. Your doctor, nurse, or pharmacist can help you check the cuff size and teach you how to use it correctly. You may also ask for their help in choosing the right blood pressure monitor for you. Blood pressure monitors can be bought at discount chain stores and drug stores.

When you are taking your blood pressure at home, sit with your back supported and your feet flat on the floor. Rest your arm on a table at the level of your heart.

After a Diagnosis

If you're diagnosed with high blood pressure, your doctor will prescribe treatment. Your blood pressure will be tested again to see how the treatment affects it.

Once your blood pressure is under control, you'll still need treatment. "Under control" means that your blood pressure numbers are in the normal range. Your doctor will likely recommend routine blood pressure tests. He or she can tell you how often you should be tested.

The sooner you find out about high blood pressure and treat it, the better. Early treatment may help you avoid problems such as heart attack, stroke and kidney failure.

See tips for talking with your doctor after you receive a medical diagnosis.