Sometimes hard lumps at the anal opening and sometimes no hard lumps are usually caused by hemorrhoids, perianal boils, sebaceous cysts and other reasons. 1. Hemorrhoids: Hemorrhoids are a common disease that occurs in the anal area, usually caused by poor bowel habits, sedentary and other reasons, patients may experience constipation, dry and hard stools, hard lumps in the anus and other symptoms. 2. Perianal boils: Perianal boils generally refer to suppurative infections of the soft tissues around the anal canal and rectum, usually caused by staphylococcal infections, poor hygiene habits, etc. Patients may experience symptoms such as redness, swelling, pain, and a foreign body in the anus. 3. Sebaceous cysts: Sebaceous cysts are usually caused by the blockage of sebaceous gland excretory ducts, usually caused by the blockage of follicular sebaceous gland orifices, unclean skin, etc. Patients may have symptoms such as foreign body in the perianal area and localized redness and swelling of the skin. With the above symptoms, it is recommended that patients should identify the cause of the disease under the guidance of the doctor and actively cooperate with the treatment to avoid aggravation of the condition.