Excluding shoe and sock staining, massage, trauma, etc., the purple coloring of the Yongquan acupoint (location: the front third of the line between the head of the seam line of the 2nd and 3rd toes and the heel in the depression at the front of the sole of the foot) may indicate cold, blood stasis, or extreme heat. It is not possible to accurately diagnose the disease based on a single symptom, and an interview with a medical professional is recommended. The skin belongs to the category of “skin” of the twelve meridians, that is, the twelve meridians in the skin part, and the meridian qi and blood through, not only to play the role of barrier defense, but also to respond to related diseases. The purple color of the skin is mostly related to cold, stasis, heat, etc. Cold symptoms are often seen cold, cold hands and feet, pain and contracture of the limbs, etc.; blood stasis is often seen local tingling, accompanied by petechiae, ecchymosis, dry and flaky skin, etc.; heat is often seen in the case of high fever, fainting, convulsions, sweating and thirst, etc.. Attention, specific identification should be combined with the four diagnosis (observation, smell, questioning and cutting), if there is any discomfort, it is recommended to consult a doctor in a timely manner.