There are several reasons for the redness, swelling and pain at the root of the thigh after rubbing: 1, it may be caused by excessive obesity, if the patient is obese, there will be a very thick layer of fat under the skin of the bilateral thighs, this kind of patients in the process of walking will easily appear between the bilateral thighs rubbing each other, which will lead to skin breakage and produce the above symptoms; 2, it may be too hot weather, the root of the thighs will be in a hot, humid environment for a long time when the weather is hot In hot weather, the root of the thigh will be in a high temperature, humid environment, at this time, if there is friction between the bilateral thighs, it is easy to cause skin damage; 3, hip-related diseases can also lead to, such as congenital genetic factors cause excessive internal closure, internal rotation of the hip joint, or cerebral palsy sequelae and other diseases that lead to excessive clamping between the bilateral hip joints, there can be long-term friction here and lead to skin lesions, the skin in this area is also easy to produce erosion 4, may be closely related to the patient’s activities, such as long-distance walking, running or horseback riding, it is easy to lead to redness, swelling and pain after friction in this area.