DEAR DOCTOR K >> I have hypertension and am on treatment. When my doctor checks the pressure, he says I'm doing "OK." Should I be monitoring my blood pressure at home?
DEAR READER >> You should definitely talk to your doctor about that. Home blood pressure monitors are easy and inexpensive, and provide you and your doctor with the information you need to protect your health.
About one in three adults in the United States has high blood pressure, or hypertension. And about half of those with high blood pressure don't have it under control. Hypertension increases the risk for heart disease and stroke. In my opinion, hypertension is one of the most important public health problems in the United States, as it affects so many people. Recognizing and treating it brings enormous health benefits.
You always have a blood pressure, every minute of the night and day, and it can change a lot from one moment to the next. What matters most to your health is where your blood pressure is on average. Before we had home blood pressure monitoring machines, the way a doctor determined if your blood pressure was controlled was to have you make a trip to his or her office.
If you think about it, that's pretty silly. The doctor is supposed to estimate what your average blood pressure is all day and all night based on one visit to the doctor's office every several months. Furthermore, many people get nervous when they visit the doctor — yes, even my patients. So their blood pressure temporarily goes up, and is higher than it normally is. Home blood pressure machines make it easy to get a much better estimate of what your average blood pressure really is.
In one study, researchers enrolled 450 people with hypertension. About half were given home blood pressure monitors that electronically sent their blood pressure readings to health professionals nearly every day. Based on these results, their medicines were adjusted and lifestyle changes were advised. The other half of the people in the study received usual care from their primary care providers.
At every step of the way, people in the home monitoring group had more success getting their blood pressure under control. The benefits persisted six months after the program had ended.
You can buy a good home blood pressure monitor for under $100. Look for:
• an automatic monitor that doesn't require a stethoscope (it's easier to use);
• a monitor that takes the blood pressure reading using a cuff that fits around the upper arm, not the wrist or finger;
• a seal of approval from a trusted organization.
Dr. Komaroff is a physician and professor at Harvard Medical School.