This pain in the medial side of the foot bunion is most commonly caused by the following two diseases: First, it is seen in bunion deformity, mainly due to genetic factors or wearing inappropriate shoes, which can lead to outward deviation of the bunion, inward turning of the first metatarsal, the first metatarsophalangeal joint in a state of subluxation, widening of the forefoot, and the first metatarsal head due to long-term friction with shoes, which can produce bunions as well as osteophytes, manifesting as local pain. Secondly, it can be seen in gouty arthritis, which is common in patients with high blood uric acid level. The formation of uric acid crystals around the first metatarsophalangeal joint leads to inflammatory reactions in soft tissues, and the repeated formation of gouty nodules can lead to chronic gouty arthritis, which can also manifest as localized painful pressure symptoms.