High blood pressure is also known as hypertension. It happens when the force of your blood pushing against the walls of your blood vessels is too high. High blood pressure can lead to other serious problems such as heart attack and stroke. It can affect all age groups: children, young adults, adults and older adults.

Your tissues and organs need the blood your circulatory system carries through the body. Your heartbeat makes this happen by pushing blood through the blood vessels. Blood pressure is the result of two forces. The first force (systolic pressure) happens as blood pumps out of the heart and into the arteries. The second force (diastolic pressure) is created as the heart rests between heart beats. These two forces are each represented by numbers in a blood pressure reading.

When blood pressure is high for too long, it can damage the walls of blood vessels, causing them to develop tiny tears. To fix these damaged areas, the body sends special cells that stick to the site. Over time, substances such as cholesterol and fats may also build up at these damaged spots, forming plaque. As plaque slowly builds, it can make the inside of the arteries narrower. This narrowing can block the flow of blood, further increasing blood pressure.

Nearly half of U.S. adults have high blood pressure. Many don’t even know they have it. The only way to know you have high blood pressure is to have your blood pressure checked.