Hypertension Blog

Hypertension affects about 20% of adults and occurs increasingly with age. Typically, the disease is more common:

• among African-Americans than whites
• among less educated people of both races
• in lower socioeconomic groups
• in men from young adulthood to age 55
• in postmenopausal women
• among African-Americans and whites living in the southeastern United States.

About 58 million Americans have hypertension. And although hypertension control has improved considerably over the past 20 years, mostly because of large-scale education programs to increase public awareness, many people with this dangerous disease still don’t know they have it.

Typically, hypertension is detected during routine physical examinations or at health fairs. After the condition has been diagnosed, treatment usually consists of lifestyle modifications and antihypertensive drug therapy, depending on the severity of the hypertension.

Blood Pressure: Normal and Abnormal

The term blood pressure refers to the force exerted by the blood against the arterial wall, usually the brachial artery wall. A blood pressure of 120/80 mm Hg is considered normal. The “120 mm Hg” is the systolic pressure-the force exerted against the arterial wall when the heart’s ventricles contract. During systole of the cardiac cycle, the elastic walls of the aorta and arteries stretch as more blood enters the ventricles. Ventricular pressure builds, causing the ventricles to contract and the aortic valve to open. The peak pressure of blood being forced through the aorta is the systolic pressure.

The “80 mm Hg” of a normal blood pressure is the diastolic pressure-the force exerted against the arterial walls when the ventricles are relaxed. During diastole of the cardiac cycle, the aortic valve closes, followed by a passive elastic recoil of the arterial walls, with a minimum amount of pressure being exerted against them. The pressure in the arteries continues to decrease during diastole, which allows the ventricles to fill with blood in preparation for the next ventricular contraction.

Patients with hypertension have either high systolic pressure, high diastolic pressure, or both. High systolic pressure is 140 mm Hg or more; high diastolic pressure is 90 mm Hg or more.

A single elevated blood pressure reading doesn’t necessarily indicate hypertension because factors such as stress, anxiety, or pain can temporarily elevate blood pressure. A physician diagnoses hypertension when a patient’s blood pressure is elevated at two different examinations. During each, readings should be taken when the patient is seated and resting comfortably. During the initial evaluation, blood pressure readings should be obtained in both arms. On subsequent evaluations, they should be taken from the arm with the higher reading.