High blood pressure is called the silent killer because it usually has no symptoms. Some people may not find out they have it until they have trouble with their heart, brain, or kidneys. When high blood pressure is not found and treated, it can cause:

• The heart to get larger, which may lead to heart failure.
• Small bulges (aneurysms) to form in blood vessels. Common locations are the main artery from the heart (aorta); arteries in the brain, legs, and intestines; and the artery leading to the spleen.
• Blood vessels in the kidney to narrow, which may cause kidney failure.
• Arteries throughout the body to "harden" faster, especially those in the heart, brain, kidneys, and legs. This can cause a heart attack, stroke, kidney failure, or amputation of part of the leg.
• Blood vessels in the eyes to burst or bleed, which may cause vision changes and can result in blindness.

The only way to find out if you have high blood pressure is to have your blood pressure measured. Blood pressure readings are usually taken when you are sitting or lying down and relaxed. Below are things you can do before getting your blood pressure taken:

• Do not drink coffee or smoke cigarettes 30 minutes before having your blood pressure taken.
• Wear short sleeves.
• Go to the bathroom before the reading. Having a full bladder can change your blood pressure reading.
• Sit for 5 minutes before the test.

Some people's blood pressure is high only when they visit the doctor's office. This condition is called white coat hypertension. If your doctor suspects this, you may be asked to check and record your blood pressure at home with a home monitor. Another way to check blood pressure away from the doctor's office is by using an ambulatory blood pressure monitor. This device is worn for 24 hours and can take blood pressure every 30 minutes.