What exactly is blood pressure? When the beating heart contracts, it pumps oxygenated blood through the arteries to your organs. Pressure is created by the force of heart contraction and by the muscular and elastic layers in the arteries. When the heart contracts and pumps blood, this is systolic pressure and when the pressure falls between contractions, this is called diastolic pressure. High blood pressure results when the elastic layers of the arteries are expanded or contracted beyond their normal capacity in a way that puts added pressure on the heart to circulate blood throughout the body. This additional stress can cause serious, and sometimes irreversible damage to vital organs and increase your risk for heart disease and stroke.

A blood pressure reading has two numbers. The first number (the top number or numerator) is the systolic blood pressure, which normally is less than 130 millimeters of mercury (mmHg). A systolic pressure between 130 and 139 mmHg is high-normal or “borderline.” Hypertension is present when the systolic pressure is at or above 140 mmHg on two separate measurements. The second number (the bottom number or denominator) is the diastolic blood pressure, which is normally less than 85 mmHg. A diastolic pressure between 85 and 89 mmHg is high-normal. Hypertension is present when the diastolic pressure is at or above 90 mmHg, on two separate measurements. If you are at high risk for developing problems from high blood pressure, such as diabetics, your doctor may want to lower it to 120/80 mmHg.

Isolated systolic hypertension is a type of high blood pressure in which only the top number is elevated, such as 160/80 mmHg. This kind of hypertension is more common in the elderly and in women and is just as important to treat as any other diagnosis of hypertension.

Many factors influence blood pressure. These include genetic factors (it may run in your family), diet, exercise, weight, alcohol, caffeine, cigarette smoking, kidney disease, stress, pain, medication, and supplements. Some of these factors may cause short-term elevations in blood pressure such as pain from having a broken ankle or even the stress of just visiting your doctor. A diagnosis of hypertension is made when several blood pressure measurements are elevated when taken under routine conditions.

Once you have been diagnosed with hypertension, it is important to have a complete history and physical. A medical evaluation will indicate if you are doing something to cause high blood pressure, if there is already damage from high blood pressure and the exam results will allow you and your doctor to create a plan to lower your blood pressure. For example, the birth control pill is associated with hypertension in about five percent of women. When the birth control pill is discontinued, this resolves. If your blood pressure is up because you have gained a lot of weight, it is also important to make sure that you have not developed other risk factors for heart disease such as high cholesterol or diabetes.

Once you have been diagnosed with hypertension, it is time to get that pressure down! Hypertension is the leading reversible cause of stroke and is also an important risk factor for heart failure, kidney failure, and heart attack. But hypertension will often not cause symptoms until stroke, kidney damage, or heart failure is already present. So don’t wait until you feel poorly to follow through with treatment.

Your doctor will likely recommend lifestyle modifications that have been shown to reduce blood pressure. These include losing weight if needed, limiting alcohol intake for women to no more than 1/2 oz of ethanol per day (for example, 12 oz of beer or 5 oz of wine or 1 oz of 100-proof whiskey each day) and twice this for men, increasing aerobic activity to 30-45 minutes most days of the week, reducing sodium intake to no more than 2400 mg of sodium per day, and maintaining adequate intake of dietary potassium. The DASH diet, which has a heavy emphasis on fruits and vegetables, has been shown to reduce blood pressure dramatically.

If these modifications are not sufficient, a drug may be prescribed. Many classes of drugs can be used to lower blood pressure such as diuretics, beta-blockers, calcium channel blockers, or ACE-inhibitors. Your doctor will try to pick the right one for you depending on your clinical profile. Some are unsafe during pregnancy so you need to let your doctor know if you are trying to conceive or are inconsistent with birth control. If you do develop side effects from your medication, it is very important to talk to your doctor about it rather than just stopping the medication until you see her next.

As we age, our chances of developing hypertension increase. More than half of all women over the age of 60 have hypertension. But with careful attention to diet, exercise, and weight management, you might avoid joining the millions of women with high blood pressure.

Resources for more information:
http://www.americanheart.org/hbp/
http://www.nhlbi.nih.gov/hbp/index.html (information on the DASH diet)