Essential hypertension refers to high blood pressure with no identifiable cause.

As blood is pumped through your body, it exerts pressure on the walls of your arteries. The systolic blood pressure is the pressure against these walls when the heart contracts, and the diastolic blood pressure is the pressure against these walls when the heart relaxes. When you get a blood pressure reading, you are told the systolic pressure/diastolic pressure.

For example, normal blood pressure is below 120/80.

High blood pressure, also called hypertension, occurs when the systolic pressure is consistently over 140 mm Hg, or the diastolic blood pressure is consistently over 90 mm Hg. Blood pressure is determined by the amount of blood pumped, by the actions of the heart, and by the size and condition of the arteries. Many factors affect blood pressure, including:

• The amount of water in the body
• The amoutn of salt in the body
• The condition of the kidneys, nervous system, and blood vessels
• Various hormone levels in the body

Prehypertension is when your systolic blood pressure is between 120 and 139 or your diastolic blood pressure is between 80 and 89. If you have prehypertension, you are more likely to develop high blood pressure at some point. Therefore, your doctor will recommend lifestyle changes to bring your blood pressure down to normal ranges.

African Americans of both sexes and Caucasian males have a higher rate of significant hypertension. While essential hypertension has no correctable cause, some genetic factors have been identified. Blood vessels become somewhat stiffer as you grow older. For this reason, the rate of high blood pressure increases with age.

Usually, high blood pressure has no symptoms at all. That is why it is often called the "silent killer." Millions of people have high blood pressure and many do not even know they have this serious condition.

Rarely, you may experience a mild headache when your blood pressure is elevated. If your headache is severe, or if you experience any of the symptoms below, you must be seen right away because these may be a sign of dangerously high blood pressure (called malignant hypertension) or a serious complication (like a heart attack).

• Fatigue
• Confusion
• Visual changes
• Nausea and vomiting
• Anxiety
• Perspiration
• Pale or red skin
• Angina-like pain, crushing chest pain

Note: There are usually no symptoms.

Blood pressure measurements are repeated over time. Systolic blood pressure consistently over 140, or diastolic blood pressure consistently over 90, is considered hypertension. Your doctor will look for signs of complications to your heart, kidneys, eyes, and other organs in your body.

Multiple systolic blood pressure readings between 130 and 139 or diastolic blood pressure readings between 80 and 89 is called prehypertension. Your doctor will recommend and encourage lifestyle changes including weight loss, exercise, and nutritional changes.

Tests for suspected causes (called secondary hypertension) may be performed. Essential hypertension is diagnosed when NO causes can be found.