Ask the Doctors | Blood pressure changes moment by moment

Dear Doctors: I’m a 69-year-old African American male with high blood pressure. I get conflicting advice from my primary care doctors, and my BP readings are never taken under the same conditions. I’m confused and losing confidence in my medical network. Can I see a specialist for hypertension?

Dear Reader: As doctors, and also as patients, we feel your plight. Blood pressure, or BP, is an important metric in maintaining good health and well-being. Yet, accurate readings often pose a challenge. A primary reason for this is that blood pressure fluctuates, not only throughout the course of the day, but also from moment to moment.

The factors that can influence someone’s blood pressure readings include general physical health, the medications or supplements they are taking, caffeine and alcohol usage, hydration, sleep, exercise, family history, their emotional state and even what they had for breakfast that morning. Check someone’s blood pressure 10 times over the course of the day, and you will receive 10 surprisingly varied measurements.

Adding to the difficulty is that blood pressure readings performed in a medical office can run artificially high. It’s common enough that there’s even a name for it: “white coat hypertension.” For this reason, in our own practices, we worry less about the numbers arrived at in the office and focus more on readings taken when someone is at home. We advise patients to check BP in the morning, while they are feeling calm and rested. These readings are usually an accurate representation of resting BP.

In the trials used to arrive at blood pressure guidelines, participants are asked to sit quietly for a set period of time prior to BP readings being taken. The effects of blood pressure medications, which are typically dosed daily, last for 24 hours. The timing of these meds should not significantly affect BP readings. The goal, according to the current guidelines, is 130/80 for everyone.

Ambulatory blood pressure monitoring, which involves wearing a device that takes dozens of readings throughout a 24-hour period, is possible. However, we don’t use this approach in our own practices. We find a week’s worth of readings taken first thing in the morning will provide an accurate and instructive average.

When we see a significant difference between morning readings and those taken later in the day, when the stressors of daily life have kicked in, that introduces questions about the tone of the nervous system. With our patients, we will open a discussion about approaches to “training” the nervous system to become less volatile. This can include deep breathing, meditation or mindfulness exercises, or practices such as yoga and tai chi. Walking, weightlifting and simply being in nature have proven to be helpful in managing blood pressure.

As to your question about working with a specialist, it is certainly an option. When blood pressure is difficult to control, a cardiologist can be helpful. Kidney problems can also contribute to hypertension. For that reason, your primary care doctor may request certain tests to see if a kidney specialist, known as a nephrologist, would be a good choice.

Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health. Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.