Blood pressure is a measure of how hard your blood pushes against the walls of your arteries as it moves through your body.
It’s normal for blood pressure to go up and down throughout the day, but if it stays up, you have high blood pressure, or hypertension.
When blood pressure is high, it starts to damage your blood vessels, heart and kidneys. This can lead to heart attack, stroke and other problems. High blood pressure is known as a silent killer, because it doesn't usually cause symptoms while it’s causing this damage.
Your blood pressure consists of two numbers: systolic and diastolic. Someone with a systolic pressure of 120 and a diastolic pressure of 80 has a blood pressure of 120/80, usually pronounced as 120 over 80.
The systolic number shows how hard the blood pushes when your heart is pumping. The diastolic number shows how hard the blood pushes between heartbeats, when your heart is relaxed and filling with blood.
High blood pressure is 140/90 or higher, but adults should have a blood pressure of less than 120/80.
Many people fall into the category in between, called prehypertension. If you have prehypertension, you need to make lifestyle changes to bring your blood pressure down. This will help prevent or delay the development of high blood pressure.
What causes high blood pressure?
High blood pressure has several common risk factors, including:
being very overweight
drinking too much alcohol
having a family history of high blood pressure
eating too much salt
Your blood pressure may also rise if you aren’t very active, you don't eat enough potassium and calcium, or you have a condition called insulin resistance.
How is high blood pressure diagnosed?
Most people find out they have high blood pressure during a routine doctor visit. For your doctor to confirm that you have high blood pressure, your blood pressure must be at least 140/90 on three or more separate occasions, usually measured 1 to 2 weeks apart.
You may have to check your blood pressure at home if there’s reason to think the readings in the doctor's office aren't accurate. You may have “white-coat hypertension,” which is blood pressure that goes up just because you're at the doctor’s office.
How is it treated?
You can help lower your blood pressure by making healthy changes in your lifestyle. If those lifestyle changes don't work, you may also need to take medication. Either way, you’ll need to control your high blood pressure throughout your life.
What can you do to prevent high blood pressure?
Making lifestyle changes can help you prevent high blood pressure. You can:
stay at a healthy weight or lose extra weight.
sat less salt and salty foods.
cut back on drinking. Limit alcohol to 2 drinks a day for men and 1 drink a day for women.