The new guidelines stem from the 2017 results of the Systolic Blood Pressure Intervention Trial (SPRINT), which studied more than 9,000 adults ages 50 and older who had systolic blood pressure (the top number in a reading) of 130 mm Hg or higher and at least one risk factor for cardiovascular disease. The study's aim was to find out whether treating blood pressure to lower the systolic number to 120 mm Hg or less was superior to the standard target of 140 mm Hg or less. The results found that targeting a systolic pressure of no more than 120 mm Hg reduced the chance of heart attacks, heart failure, or stroke over a three-year period.
Healthcare professionals use a stethoscope and a manual sphygmomanometer to measure your blood pressure. Typically they take the reading above your elbow. The sphygmomanometer has a bladder, cuff, bulb, and a gauge. When the bulb is pumped it inflates the bladder inside the cuff, which is wrapped around your arm. This inflation will stop the blood flow in your arteries. The stethoscope is used to listen for sound of the heartbeat, and no sound indicates that there is no flow. As the pressure is released from the bladder, you will hear the sound of the blood flowing again. That point becomes systolic reading. The diastolic reading is when you hear no sound again, which means that the blood flow is back to normal.
If your blood pressure remains high for a long period of time, you run the risk of damaging your blood vessels. Your stroke risk rises significantly, too. And because your heart is working harder to push blood through your system, that very valuable muscle can become overworked and grow thicker. An enlarged heart causes further complications, including heart failure. Medications and special implantable pumps can help boost heart function. But if you can manage your blood pressure before it gets too high and puts your heart at risk, you may be able to avoid a lot of complications down the road.
"Blood pressure guidelines are not updated at regular intervals. Instead, they are changed when sufficient new evidence suggests the old ones weren't accurate or relevant anymore," says Dr. Paul Conlin, an endocrinologist with Harvard-affiliated VA Boston Healthcare System and Brigham and Women's Hospital. "The goal now with the new guidelines is to help people address high blood pressure — and the problems that may accompany it like heart attack and stroke — much earlier."