Hypertension or High Blood Pressure is often called the silent killer because you can have it for years without knowing it. Hypertension is a medical condition in which constricted arterial blood vessels increase the resistance to blood flow, causing an increase in blood pressure against vessel walls. The heart must work harder to pump blood through the narrowed arteries. If the condition persists, damage to the heart and blood vessels is likely,

Under new, stricter national blood pressure guidelines issued in May 2003, a resting blood pressure reading below 120/80 millimeters of mercury (mm Hg) is normal. If your resting blood pressure is consistently 140/90 mm Hg or higher, you have high blood pressure. A reading in between these levels places you in the prehypertensive category. Under the new guidelines, a reading of 115/75 is the level above, which your risk of cardiovascular complications starts to increase.

Many people may not view a blood pressure above 115/75 as life threatening because there are few, if any, symptoms. But uncontrolled high blood pressure can increase your risk of stroke, heart attack, heart failure and kidney failure. Fortunately, high blood pressure can be detected with a simple test — and once you know you have high blood pressure, you can work with your doctor to control it.

Most people with high blood pressure have no signs or symptoms. Even so, people often think that headaches, dizziness or nosebleeds are common warning signs of high blood pressure. It's true that a few people with early-stage high blood pressure have a dull ache in the back of their heads when they wake in the morning. Or perhaps they have a few more nosebleeds than normal.

Headaches, dizziness or nosebleeds typically don't occur until high blood pressure has advanced to a higher stage — one that's possibly life-threatening. Even so, most people with the highest blood pressure readings don't experience any of these symptoms.

Other conditions that can lead to uncontrolled high blood pressure cause the following signs and symptoms:

• Excessive perspiration
• Muscle cramps
• Weakness
• Frequent urination
• Rapid or irregular heartbeat (palpitations)

• Blood pressure is taken with an inflatable arm cuff connected to a pressure-measuring unit — a device called a manometer (sphygmomanometer). Your blood pressure generally isn't considered high unless the average of three pairs of readings in a row is elevated, each pair taken at different visits to your doctor under similar conditions.
• Your doctor is also likely to do the following:
  • Ask you questions about your health and your family's health (a health history).
  • Do a physical examination.
  • Ask you to have routine tests such as urine test (urinalysis), a blood test or an electrocardiogram (ECG), which measures your heart's electrical activity.
  • Consider the need for more specialized tests to examine blood flow. These tests may include ultrasonography, magnetic resonance angiography, angiography, computerized tomography (CT), magnetic resonance imaging (MRI) or nuclear scanning. They're especially important if your doctor is looking for secondary causes of hypertension.