What is Blood Pressure?

Like water pressure in a pipe, blood pressure is how much force is in your arteries as blood flows through them. It should not be too low (hypotension) or too high (hypertension, or HTN).

Blood pressures are given as two numbers. The systolic pressure (top number) is the pressure when your heart is forcing out the blood when it squeezes. The diastolic pressure (bottom number) is the pressure when your heart is resting between beats. The unit for blood pressure is millimeters of mercury (mmHg). Even a drop in the top (systolic) number by 2-5 mmHg is tied to a 7% lower risk of dying when someone’s pressures are up.

How do you know if your pressure is high? Most groups agree that anything less than 120/80 is normal. And 140/90 or above is quite high. The harm from high blood pressure increases with every point it goes up, so some groups, like the American Heart Association, say even a top number of 130 is high, compared to 120.¹ Talk to your care team about your own blood pressure goals.  Your goals may be different if you have other health problems, like kidney disease or diabetes, or based on your age. Remember only one of the two numbers - top or bottom - needs to be up to say the blood pressure reading is high. You need at least two high readings at two different medical visits for it to be called hypertension. 

It is good for most people to keep blood pressure above 90/60. If it is over 180/120, that could be what is called a “hypertensive crisis.” If you get a reading that is that high, check it again after 5 minutes and call a care provider right away if it stays up. If very high pressures like that are accompanied by symptoms like chest pain, shortness of breath, numbness, weakness, speech problems, or vision changes, call 911.

Why Does Blood Pressure Matter? 

Nearly half of all adults have HTN, based on the strictest limits for high readings. Only 1 out of every 4 people with HTN have their pressures under control. We know that lowering blood pressure prevents a lot of health problems and helps you live longer.

Over time, high blood pressure can hurt the body in different ways. For example, it puts people at greater risk for heart problems, like heart attacks or heart failure. Having a healthy blood pressure also protects against problems like kidney disease, stroke, memory loss, eye problems, and blocked arteries in the legs. For men, HTN increases their chances of having erection problems.

HTN is called “the silent killer.” Some people don’t worry too much about high blood pressure because they do not feel it. But high blood pressure can cause harm whether you feel it or not.  It can seem strange to treat something if you can’t tell it is causing you problems but doing that is very important to prevent problems later.