Nerve damage caused by massage is a rare occurrence, but it is still a common concern. While it is possible for too much massage to be harmful, it is important to listen to your body and communicate openly with your masseuse. Sports performance may be slightly affected by pre-event massage, but this is usually a minor consideration. There is evidence that massage can damage muscles, as there are several case studies of rhabdomyolysis.
Post-massage pain and discomfort (PMSM) is a common phenomenon, but it can also be caused by other physical and metabolic tensions. It is important to consult your massage therapist if you have any health conditions or are pregnant, and to reveal any previous injuries. Headaches can be aggravated by massage, so it is important to communicate any pain or discomfort to the masseuse. In rare cases, massage can damage the radial nerve, the spinal accessory nerve, the posterior interosseous nerve, and others.
However, massage performed by trained professionals is generally safe. If the masseuse continues with what they are doing after you ask them to stop, this is a major warning sign.