OBJECTIVETo explore the scientificity of Yunqi theory based on incidence of disease related recognitions such as year evolutive phase, host climatic qi, six climatic factors, celestial manager qi, qi in the earth by analyzing data of hypertension incidence.

METHODSA total of 1,265 inpatients with confirmed first diagnosis as hypertension were recruited at Dongzhimen Hospital, Beijing University of Chinese Medicine from February 4, 1999 to February 4, 2011. Each period (including year evolutive phase, host climatic qi, guest climatic qi) was deducted based on Yun-qi theory. Their ratios of different phases and qi in the total number of hypertension inpatients number were calculated and statistically tested.

RESULTSThere was statistical difference in ratios at year evolutive phase, celestial manager qi, and qi in the earth (P < 0.05).

CONCLUSIONThe incidence of hypertension has certain difference in each period, which is consistent with Yun-qi theory.