Hypertension is abnormally high blood pressure in the arteries, which are the blood vessels that carry blood from the heart to the rest of the body. As the heart beats, it forces blood through the arteries to deliver nutrients and oxygen to the rest of the body. The strength of the blood pushing against the artery walls is blood pressure, which is measured in units called millimeters of mercury (mmHg). The top number in a blood pressure reading is the pressure when the heart pumps (systolic blood pressure), and the bottom number is the pressure between heart beats (diastolic blood pressure). In adults, a normal blood pressure measurement is about 120/80 mmHg. Blood pressure is considered high when the measurement is 130/80 mmHg or greater.
Hypertension can have a variety of causes. Secondary hypertension results from other disorders that raise blood pressure in addition to other problems. Rare, genetic forms of hypertension are caused by mutations in particular genes, many of which help control the balance of fluids and salts in the body and affect blood pressure. The causes of essential hypertension, however, are not well understood. Essential hypertension is a complex condition with a variety of factors, both genetic and environmental, contributing to its development.
Hypertension affects an estimated 47 percent of adults in the United States. Prevalence of the condition increases with age, and approximately 70 percent of people over age 65 are affected. In African Americans, the condition is more common, starts at a younger age, and is more severe than in other populations.
Hypertension tends to run in families. Individuals whose parents have hypertension have an elevated risk of developing the condition, particularly if both parents are affected. However, the inheritance pattern is unknown.
Published Date: January 01, 2019Published By: National Institutes of Health