Common side effects of fat breast augmentation surgery include infection, fat liquefaction, bleeding, asymmetry in the size of both breasts and hard lumps. 1. Infection: If the sterilization is not strict during the fat breast augmentation surgery, it will easily lead to infection at the wound site, resulting in redness, swelling and hot pain. 2. Fat liquefaction: If the amount of fat filled is large, it is easy to cause the fat to accumulate into lumps and the phenomenon of fat liquefaction occurs. 3. Bleeding: If the small blood vessels in the breast are damaged during the operation or if there is a blood clotting mechanism disorder, the phenomenon of blood will easily appear after the operation. 4. Breast size asymmetry: If the amount of fat filled on both sides is not uniform, it will easily lead to asymmetry in the size of both sides of the breast. 5. Hard lumps: If the fat filled during the operation is not uniform and more fat gathers in one piece, it will easily lead to fibrous nodules, thus hard lumps will appear. It is recommended to go to authoritative and qualified hospitals for fat breast augmentation surgery, as these hospitals generally have better medical conditions, and the effect and safety are more guaranteed.