Objective To observe the meridian-acupoint reactions of foot three yin meridians in primary dysmenorrhea(PD) and secondary dysmenorrhea(SD) patients

so as to summarize the rules of meridian-acupoint reaction and acupoints selection. Methods Thirty-five patients with PD(PD group)

34 patients with SD(SD group) and 35 healthy subjects(healthy group) were recruited. The compression method was used to examine the lower leg segment of the foot three yin meridians. Positive reactions(palpable skin changes

including cords

nodules

depressions) and tenderness of meridians and acupoints were recorded. The visual analogue scale(VAS) was used to evaluate the tenderness severity of acupoints. Results Compared with the healthy group

the probability of positive reactions and tenderness in foot three yin meridians were higher in PD and SD groups(P<0.01

P<0.05). Compared with the PD group

the probability of positive reactions in Spleen and Liver Meridians were higher in the SD group

with higher probability of tenderness in Liver Meridian(P<0.05). The probability of positive reactions and tenderness in the Spleen Meridian of PD and SD groups was significantly higher than that in the Kidney Meridian(P<0.01)

while the probability of tenderness in the Spleen Meridian of the PD group was significantly higher than that in the Liver Meridian(P<0.05). Positive reactions and tenderness were concentrated at Yinlingquan(SP9)

Diji(SP8) and Sanyinjiao(SP6) of Spleen Meridian and Xiguan(LR7) and Ligou(LR5) in Liver Meridian of PD and SD groups. In comparison with the PD group

the probability of positive reactions

tenderness and VAS score of SP8 and LR5 of the SD group were higher(P<0.05

P<0.01). Conclusion The positive reaction occurs most frequently in the Spleen Meridian

followed by the Liver Meridian

and least frequently in the Kidney Meridian. The acupoints with positive reaction are different between PD and SD

which suggests that the Spleen Meridian acupoints should be the main acupoints when treating the two kinds of dysmenorrhea

and acupoints should also be selected according to the meridian and acupoint examination results.