A large hard bump on the back may be related to personal habits, due to inadequate cleaning or collision with hard objects can lead to the appearance of a hard lump on the back. Hard bags may also be caused by disease factors, including acne, folliculitis, lipoma, fibroids, etc. The first two are generally caused by skin inflammation, the latter two are mostly subcutaneous restricted lumps. I. Skin inflammation 1. Acne: Acne is caused by increased or relatively increased levels of androgens, resulting in excessive oil secretion and hyperkeratosis of the follicular sebaceous gland opening, which leads to the inability to discharge oil normally and the accumulation of oil at the mouth of the follicle, coupled with secondary Propionibacterium acnes infection, resulting in chronic inflammatory disease of the follicular sebaceous gland unit, which in turn leads to acne. It can be treated by oral antibiotics, such as doxycycline, minocycline, and isotretinoin, and topical treatment with retinoic acid cream, peroxynivalenol, antibiotics, and azelaic acid. 2. Folliculitis: It is a group of bacterial infectious skin diseases involving hair follicles and surrounding tissues, which also appear as hard pockets, and the patient is accompanied by significant pain as well as fever, and there will be significant local bleeding, redness, swelling, and tenderness on examination. Choose broad-spectrum penicillin for anti-inflammatory treatment, and if an abscess is formed, it should be incised and drained, and if necessary, choose cross incision, and pay attention to intravenous anti-infection treatment after the operation, and change medication regularly. Second, limited masses 1, lipoma: if small, generally no treatment is needed, regular observation can be done. Those with more obvious symptoms and larger lipomas that affect aesthetics need surgery. Postoperative antibiotics such as amoxicillin and cefdinir can be used prophylactically for anti-infection treatment; 2. Fibroids: medication or surgery can be chosen, among which triamcinolone acetonide and ginsenoside can be chosen for medication, and surgery includes a wider area around the involved tissue, and part of the involved whole muscle needs to be removed. Postoperative pathological examination and appropriate oral anti-infective drugs are performed.