Controversies in Hypertension III: Dipping, Nocturnal Hypertension, and the Morning Surge

A comprehensive approach to hypertension requires out-of-office determinations by home or ambulatory monitoring. The 4 phenotypes comparing office and out-of-office pressures in treated and untreated patients include normotension, hypertension, white-coat phenomena, and masked phenomena. Compo-nents of out-of-office pressure may be equally as important as mean values. Nighttime pressures are nor-mally 10%-20% lower than daytime (normal "dipping") pressures. Abnormalities include dipping more than 20% (extreme dippers), less than 10 % (nondippers), or rising above daytime (risers) and have been associated with elevated cardiovascular risk. Nighttime pressure may be elevated (nocturnal hypertension) in isolation or together with daytime hypertension. Isolated nocturnal hypertension theoretically changes white-coat hypertension to true hypertension and normotension to masked hypertension. Pressure normally peaks in the morning hours ("morning surge") when cardiovascular events are most common. Morning hypertension may result from residual nocturnal hypertension or an exaggerated surge and has been associ-ated with enhanced cardiovascular risk, especially in Asian populations. Randomized trials are needed to determine whether altering therapy based solely on either abnormal dipping, isolated nocturnal hyperten-sion, or an abnormal surge is justified. & COPY; 2023 Elsevier Inc. All rights reserved. & BULL; The American Journal of Medicine (2023) 136:629-637