The 35-year-old Mr. Liu has recently developed perianal swelling and pain, holding the psychology that it is a minor disease such as hemorrhoids, so he did not go to the hospital to see, but just went to the pharmacy to buy hemorrhoid medicine to treat. However, a week later the symptoms are not relieved but gradually aggravated, but also fever, rushed to the hospital to see. After being admitted to the hospital, the temperature was as high as 39.0°C. The examination revealed redness and swelling around the anus, which was diagnosed as perianal abscess, and the symptoms were relieved only after emergency surgery. The disease Mr. Liu suffered from, “perianal abscess”, is called perianal abscess, or canker sore in Chinese medicine, and is the result of an acute purulent infection of the soft tissue around the anus and rectum. Perianal abscess can develop at any age, but it is more common in young and middle-aged people aged 20 to 50, more in men than in women, and can also develop in infants and children. The onset of perianal abscess is more sudden and fast progressing, which can cause severe local pain in the perianal area and fever and other systemic symptoms in severe cases. Perianal abscesses should be treated seriously after they occur, because abscesses are not easily absorbed on their own, and drainage is often poor even if they break outward, so once an abscess is formed, surgery is the only reliable method, and the sooner it is treated, the better. Waiting for its self-rupture only invites the risk of spreading inflammation and aggravates the pain. If left untreated, it may also lead to infectious shock and even endanger life. Therefore, once the painful perianal swelling occurs, do not “diagnose” and “treat” yourself, and the best choice is to go to a specialist in a timely manner.