The Japanese Society of Hypertension Practical Consensus Guidelines for Seasonal Blood Pressure Management

Cardiovascular diseases show distinct seasonal occurrence patterns, in which BP fluctuations, exposure to cold or high temperatures, and changes in autonomic nervous system activity play important roles [ 44 ]. In Japan, where seasonal climatic changes are pronounced, these effects may be further amplified by an aging population and house-related environmental factors [ 45 ]. During winter, the incidence of cardiovascular diseases, intracerebral hemorrhage, and cardioembolic stroke increases in association with elevated BP, sympathetic nervous system activation, and increased blood viscosity. In summer, dehydration, heat stress, and exposure to high temperatures may increase the risk of cardiovascular events and non-cardioembolic ischemic stroke. Of the four seasons, winter appears to be associated with the greatest overall risk of cardiovascular disease onset. Accordingly, seasonally-adapted BP management should incorporate comprehensive year-round strategies, including protection from cold and careful BP control during winter, as well as appropriate adjustment of antihypertensive therapy, adequate hydration, and prevention of heat-related illness during summer. In addition, the growing impact of extreme weather events associated with climate change, including heat waves, torrential rainfall, cold spells and heavy snowfall, cannot be overlooked. Seasonal variation should therefore be regarded not simply as an environmental phenomenon, but as a potentially modifiable component of cardiovascular risk. Integrating meteorological information with clinical data may facilitate the implementation of seasonally tailored management of hypertension and cardiovascular diseases in both clinical practice and community healthcare. Public education is also important, particularly during seasonal transitions and other high-risk periods, to improve awareness of the early symptoms of cardiovascular and cerebrovascular diseases that are more likely to occur during those seasons, and to promote timely medical consultation when such symptoms develop.