I have hypertension. What’s the best time of day to check my pressure? —W.J.L., Alexandria, Va.

Measure it at various times to determine when it’s typically highest, then check it at that time each day; that provides the best information about possibly worrisome elevations. But also measure your blood pressure if you experience symptoms such as lightheadness, which might stem from too much antihypertensive medication. To ensure reliable results, rest your arm in the same position whenever you take a measurement, and wait a half-hour after exercising or consuming caffeine, which can increase your pressure, or after eating, which can lower it.