Blood pressure fluctuates throughout the day, responding to the body’s activity levels. In healthy individuals, blood pressure typically decreases during sleep as the heart and nervous system enter a resting state. This natural nighttime dip is crucial for overall cardiovascular health. However, consistently elevated blood pressure during the night, a condition sometimes referred to as nocturnal hypertension, can be more dangerous than daytime hypertension. The lack of this nighttime reduction puts increased strain on the cardiovascular system during a vulnerable period. Further research explores the implications of this phenomenon for long-term health outcomes in Việt Nam. Understanding these patterns is essential for effective management and prevention of cardiovascular disease.