Definition of Hypertension:

Hypertension is the term used to describe high blood pressure.

Blood pressure is a measurement of the force against the walls of your arteries as your heart pumps blood through your body.

Blood pressure readings are usually given as two numbers -- for example, 120 over 80 (written as 120/80 mmHg). One or both of these numbers can be too high.

The top number is called the systolic blood pressure, and the bottom number is called the diastolic blood pressure.

• Normal blood pressure is when your blood pressure is lower than 120/80 mmHg most of the time.
• High blood pressure (hypertension) is when your blood pressure is 140/90 mmHg or above most of the time.
• If your blood pressure numbers are 120/80 or higher, but below 140/90, it is called pre-hypertension.

If you have pre-hypertension, you are more likely to develop high blood pressure.

If you have heart or kidney problems, or if you had a stroke, your doctor may want your blood pressure to be even lower than that of people who do not have these conditions.

Causes, incidence, and risk factors:

Many factors can affect blood pressure, including:

• How much water and salt you have in your body
• The condition of your kidneys, nervous system, or blood vessels
• The levels of different body hormones

You are more likely to be told your blood pressure is too high as you get older. This is because your blood vessels become stiffer as you age. When that happens, your blood pressure goes up. High blood pressure increases your chance of having a stroke, heart attack, heart failure, kidney disease, and early death.

You have a higher risk of high blood pressure if you:

• Are African American
• Are obese
• Are often stressed or anxious
• Drink too much alcohol (more than one drink per day for women and more than two drinks per day for men)
• Eat too much salt in your diet
• Have a family history of high blood pressure
• Have diabetes
• Smoke

Most of the time, no cause of high blood pressure is found. This is called essential hypertension.

High blood pressure that is caused by another medical condition or medication is called secondary hypertension. Secondary hypertension may be due to:

• Chronic kidney disease
• Disorders of the adrenal gland (pheochromocytoma or Cushing syndrome)
• Pregnancy (see: preeclampsia)
• Medications such as birth control pills, diet pills, some cold medications, and migraine medications
• Narrowed artery that supplies blood to the kidney (renal artery stenosis)
• Hyperparathyroidism