Dr. Roach: How do you know when you really need blood pressure meds?
Dear Dr. Roach: I’m a 71-year-old female who is basically in good health. I am active and still working. I usually walk 3 miles per day, five days per week, and try to stay limber by doing strength training and stretching to enhance my health. I eat healthy with low salt and hardly any caffeine. I tend to have high reactions to drugs.
How do you know when you really need blood pressure medicine? I have received conflicting advice. For example, I have been told that blood pressure is a cycle in that it is lowest when sleeping, rises in the morning and continues to rise during the day and then starts to go down at night; however, I’ve been told it should be kept to 120/80. I also read that as you get older it is natural and OK for the systolic to be 135. After walking and breakfast, many times I have pressure ranging from 104/65 to 134/72. I noticed that occasionally the systolic may hit 140 but rarely, and that is usually in the afternoon or at a doctor’s office.
Dear D.C.S.: Variations in blood pressure send many people to see their medical doctor, and we know a great deal about its complications and treatment. It is somewhat surprising, then, that there remains uncertainty about deciding who needs treatment. Nonetheless, there is increasing certainty with the publication of new studies.
More information about a person’s blood pressure is better: A single reading a few times a year at a doctor’s office is not the optimal amount of data. A high-quality home blood pressure cuff is a great way to get additional information. The more readings, the better the picture.
Blood pressure does go up and down normally, and so it is the average blood pressure that you want to know. As you correctly said, blood pressure at night tends to be lower than during the day, so there are standards for average daytime (130/80) and nighttime (110/65).
A 24-hour ambulatory blood pressure monitor has become the definitive method of measuring blood pressure, and is a better predictor of the types of events we are trying to prevent (heart attack, stroke) than office blood pressures. Unfortunately, it is harder than it ought to be to get a 24-hour monitor paid for by insurance.
In absence of a 24-hour blood pressure monitor, getting many readings throughout the day is likely to be a better guide to when treatment is necessary than just the doctor’s office. Blood pressure can go up if a person is anxious or nervous; this is called white-coat or reactive hypertension if in a doctor’s office. While an occasional reading of 135 or 140 is not a problem, an average systolic over 130 is higher than optimal. Treatment even of that low number does reduce the risk of heart attack and stroke, at least in people who had additional risks for heart disease.
You and your doctor should check your average reading to decide whether treatment will be helpful.
Readers may email questions to ToYourGoodHealth@med.cornell.edu.