A hard and painful bump on the side of the anus is considered to be caused by thrombosed hemorrhoids or perianal scabies. Thrombosed hemorrhoids are mainly caused by excessive consumption of spicy and irritating foods and excessive straining during bowel movements, which cause the perianal subcutaneous veins to break and bleed and accumulate in the subcutaneous tissue. Scabies is caused by purulent infection of hair follicles and perifollicular tissues, especially in the perianal area, which is contaminated with feces and urine for a long time and is prone to poor hygiene and staphylococcal infections, etc. The initial stage of scabies is localized redness, swelling, and pain, and patients with severe symptoms may develop fever, increased white blood cell count, and general discomfort, The initial stage of scabies will be localized redness, pain, and fever, increased white blood cell count, and general discomfort.