Range of BP readings can be telling

Dear Dr. Roach: My doctor recently retired, my new one is very concerned about my systolic blood pressure, which was 150. I made quarterly visits to my old doctor, who never had a comment about my pressure numbers. My new doctor wants me on medication, and we agreed I would buy a home blood pressure machine to check my pressure.

I recorded it for 21 days, sometimes more than once day. My systolic numbers range from 118 to 150 and average 132. Out of 26 times, it was 150 once.

My diastolic numbers are pretty consistent in the midto low 80s.

I sat still at my desk for these tests. Is seeing such a range a concern?

T.H.

Answer: Your average blood pressure is modestly elevated. The range of readings you are asking about is not unusual. Blood pressure always varies throughout the day.

Given that you are otherwise apparently at low risk (no diabetes, nor heart or vascular disease), I do not think there is a compelling reason to start medication therapy.

You can help keep blood pressure down by eating a diet that is lower in salt, getting regular exercise and managing stress.

Dear Dr. Roach: You recently wrote a column on taking high blood pressure medications later in the evening, specifically near bedtime. It is my understanding that some people’s blood pressure will drop so low in this situation the perfusion pressure to the optic nerve will be insufficient. This can lead to glaucomalike atrophy of the nerve, potentially leading to loss of function. It seems careful follow up to determine if loss of optic nerve is occurring should be recommended.

K.S.

Answer: Dropping the blood pressure too quickly can limit blood flow to the brain, and the retina is in fact brain tissue. However, the medicines for high blood pressure in common use now do not suddenly drop blood pressure to the point where there is a risk of damage to the tissues. The brain has a highly developed ability to maintain blood flow across a wide range of blood pressures.