Sometimes anal swelling after a while will be fine, consider and sinusitis, hemorrhoids, gynecological diseases and other conditions related. 1. Sinusitis: If the patient’s diet is not appropriate or the anal area is infected, it may induce sinusitis, which is an inflammatory lesion of the anal crypt. Typical symptoms are pain in the anus during bowel movement, which may be accompanied by irregular anal swelling. 2. Hemorrhoids: may be related to long-term constipation or bad habits, the main symptom for the anal area hemorrhoids, hemorrhoids will gradually red and swollen hemorrhoids enlargement. In severe cases, patients will experience anal swelling, painful defecation, blood in the stool and anal itching and other symptoms. 3. Gynecological diseases: if the patient belongs to women, due to uterine fibroids or pelvic inflammatory disease, with the fibroids or inflammation of the tissue increases, it will press to the rectum, causing anal swelling feeling. To summarize, there may be other factors that cause anal distension, so we suggest that patients actively seek medical attention, cooperate with doctors to do systematic examination, clarify the cause of the disease, and give treatment as soon as possible.