The common causes of anal swelling and dampness are: internal hemorrhoids, proctitis, sinusitis, and so on. 1. Internal hemorrhoids: As internal hemorrhoids appear above the dentate line, in severe cases there will be the formation of embolus, that is, hemorrhoidal nuclei, and hemorrhoidal nuclei will stimulate the nerves around the anus, which in turn produces a feeling of anal swelling. The hemorrhoidal nucleus will also lead to poor closure of the anal opening, and then cause anal moisture. 2. proctitis: due to inflammation stimulation of rectal mucosa, can cause mucosal edema, resulting in mucosal thickening, narrowing of the anal canal, when defecation, feces will produce mechanical stimulation of the intestinal tract and the anal canal, which in turn appear anal distension. In addition, the inflammatory mediators will also lead to an increase in the secretion of the mucous membrane, which will lead to mucus outflow from the anus, resulting in anal wetness. 3. Sinusitis: it is due to the repeated bacterial infection of the anal crypt, which can cause anal sphincter muscle tension, spasm, swelling and other manifestations, and then make the patient feel anal swelling. Inflammation can also lead to an increase in local secretions, resulting in anal moisture, itching and other manifestations. In short, when the anal sensation of swelling, moisture, and other symptoms of discomfort, it is recommended to go to the hospital, a clear diagnosis, and follow the doctor’s instructions to give targeted treatment.