The goal of treating hypertension is to prevent the development of cardiovascular and cerebrovascular disease. A number of studies have suggested that 24-hour ambulatory blood pressure levels can more accurately predict the occurrence of cardiovascular complications. Important developments regarding the relationship between blood pressure and cardiovascular disease include the following: 1. In untreated individuals, the value of daytime and nighttime blood pressure levels for predicting the risk of developing cardiovascular and cerebrovascular disease is similar. 2. For those receiving antihypertensive therapy, nighttime blood pressure is a better predictor of the likelihood of cardiovascular events. The results of a comprehensive analysis of data from the recently published International Ambulatory Blood Pressure Database (n=7458) suggest that daytime and nighttime blood pressure have similar predictive value for fatal and nonfatal cardiovascular disease in subjects not taking any antihypertensive medication. The higher the nocturnal blood pressure, the greater the risk of cardiovascular and noncardiovascular death; the lower the daytime blood pressure, the greater the risk of noncardiovascular death, and the reason for the increased risk was not from low blood pressure per se. In patients treated with antihypertensive therapy, only nocturnal blood pressure was independently associated with cardiovascular events, while daytime blood pressure was not. 4. The nighttime to daytime blood pressure ratio independently predicted the risk of death. The higher the nighttime to daytime blood pressure ratio, the greater the risk of death, i.e., the risk of stroke is significantly higher in non-Arytenoid blood pressure (nighttime to daytime blood pressure ratio >0.9) than in Arytenoid blood pressure (nighttime to daytime blood pressure ratio between 0.8 and 0.9). Therefore, the nocturnal blood pressure drop rate is very important. 5. Patients with pure nocturnal hypertension have demonstrated some degree of vascular impairment. It may be an earlier manifestation of hypertension. Only through 24-hour blood pressure monitoring can we know the daytime and nighttime blood pressure levels and their changes, obtain the nighttime blood pressure to daytime blood pressure ratio, the nighttime blood pressure drop rate, detect simple nocturnal hypertension, diagnose white coat hypertension, and also detect nighttime and daytime hypotension. Therefore, it is recommended that people with hypertension should receive 24-hour blood pressure monitoring.