In this study, the hypertensive individuals are consecutively recruited from multiple centers, with an early onset age (less than 40 when diagnosed). A complete clinical history (information on history of hypertension, demographic characteristics, personal and family medical history) are collected by a trained staff using a standardized questionnaire on the first day of baseline observation, and physical examination are also collected in a standard procedure. Blood samples are collected after 12-hour overnight fast and biological variables are determined. Genomic DNA is isolated from leukocytes according to a standard procedure. The individuals will receive follow-up in an ordinal system. The investigators will focus on the clinical and genetic features, genotype-phenotype correlations and influencing factors of prognosis in Chinese early-onset hypertension patients.