Objective To clarify the characteristics of infrared thermal imaging in pre-hypertension, and provide the basis for early diagnosis and treatment of hypertension. Methods 150 cases of patients selected from Preventive Treatment of Disease Center of Yueyang Hospital of TCM in March -June 2015, who were randomly divided into 3 groups:pre-hypertension group, hypertension group and healthy volunteers group 50 cases in each group. The infrared thermal images in face, precordial and back regions of all groups were given the qualitative and quantitative analysis. Results Deep red image in the head an...