Redness and swelling around the anus may be caused by perianal abscess, anal eczema, hemorrhoids and other reasons. 1. Perianal abscess: when the anal canal and rectal peripheral tissues are infected by pathogenic bacteria such as Escherichia coli and Staphylococcus aureus, causing localized purulent masses, and if there is a rupture, so that the local skin is moist, then there will be redness and swelling around the anus, and there may be localized symptoms of severe pain as well. 2. anal eczema: when the anal environment is too moist, will make the local skin pimples, if the bacteria, viruses and other factors of infection, will lead to the symptoms of redness and swelling around the anus, some patients may also be accompanied by itching phenomenon. 3. Hemorrhoids: when a long time bad eating habits, do not pay attention to personal hygiene or constipation, so that the hemorrhoidal nucleus appeared to be stagnant and swollen, such as caused by the intestinal tract of the tissue fluid outflow, will make the surrounding environment become moist, leading to the symptoms of redness and swelling around the anus, and may be painful, the phenomenon of blood in the stool. Causes of perianal redness and swelling of more causes, should also go to the hospital in time for examination, clear causes given targeted treatment to avoid aggravation of the condition.