There are several possible reasons for painful back lipoma: 1. It may be that the growth rate of lipoma is relatively fast. The tension of the envelope on the surface of the lipoma is relatively high, which can easily form a painful lipoma, and the patient will experience painful lipoma when pressing or peritoneum. 2. It may be due to the long-term repeated compression of the back lipoma in the lying position or resting or sleeping for a long time, which can easily cause changes in the local ischemia of the lipoma and can also cause painful lipoma. 3. It may be due to the malignant transformation of the lipoma, which is relatively rare in this case and chance It may also cause rapid increase of lipoma in the corresponding area, swelling and pain. If you have back lipoma pain, it is best to go to the hospital in time for an early consultation.