February is American Heart Month. This provides an opportunity to focus on cardiovascular health. The Centers for Disease Control and Prevention has a division that is focused on high blood pressure and hypertension, in large part due to the fact that hypertension is a leading risk factor for heart disease and stroke. The agency has also encouraged a shift towards a focus on monitoring blood pressure (BP) at home in addition to the data gathered at medical appointments.
The Mayo Clinic defines:
- Normal blood pressure. Blood pressure is 120/80 mm Hg or lower.
- Elevated blood pressure. The top number ranges from 120 to 129 mm Hg and the bottom number is below, not above, 80 mm Hg.
- Stage 1 hypertension. The top number ranges from 130 to 139 mm Hg or the bottom number is between 80 and 89 mm Hg.
- Stage 2 hypertension. The top number is 140 mm Hg or higher or the bottom number is 90 mm Hg or higher.
Blood pressure higher than 180/120 mm Hg is considered a hypertensive emergency or crisis. Seek emergency medical help for anyone with these blood pressure numbers.
The importance of monitoring BP at home
BP measurements taken in medical offices are prone to error. Variables that can result in inaccurate readings within the office include the patient talking while taking the BP reading, use of tobacco prior to the reading, a full bladder, a failure to properly calibrate the device, or inappropriate application of the BP cuff. These errors can be significant and reportedly range from a reading that is off by 2 mm Hg to more than 30 mm Hg.
Medical professionals note that these errors often fall into one of two categories: white-coat hypertension and masked hypertension. White-coat hypertension refers to those who have inaccurately high BP measurements while in a health care provider’s office or another medical setting. This can result in dangerous and unnecessary medical intervention. In contrast, masked hypertension occurs when an individual has an inaccurate normal reading in the office but has hypertension. This leads to the dangerous undertreatment of hypertension.
The American Heart Association and the United States Preventive Services Task Force recommend the use of home BP monitoring (HBPM) to get a better grasp on the presence of hypertension. Research supports the fact that HBPM is more likely to predict cardiovascular disease compared to office BP measurements.
It is important to use proper HBPM techniques to better ensure accuracy. This includes the use of a device that passes validation protocols and uses an upper-arm cuff to gather the measurement. Additional technique guidance to increase accuracy includes:
- Measure twice in the morning and twice at night
- Continue these measurements for at least three days
- Record both the systolic and diastolic numbers
- Once measurements are stable, monitor them one to three days per week
It is also wise to receive training from medical experts before beginning to monitor one’s own BP.
Successful HBPM can result in early diagnosis and get treatment on track. The use of HBPM in collaboration with medical visits can reduce the risk of kidney failure, damage to arteries, aneurysm, stroke and heart failure.