Ask the doctor: Should I worry about low nighttime blood pressure?

Q. My systolic blood pressure is high in the morning (about 165), but in the evening it drops to below 100. I am taking two blood pressure medications daily and still experiencing seriously low blood pressure at night. What would you suggest?

A. Everyone's blood pressure changes throughout the day, and it's often highest in the morning and lowest at night. You seem worried about the low pressure at night, but that would concern me only if it's accompanied by symptoms such as dizziness or fainting. A systolic (top number) pressure below the normal of 120 is usually not worrisome. In fact, studies show that low blood pressure while you are sleeping predicts low cardiovascular risk.