Osteomyelitis does not cause pain all the time, but only when the inflammation erodes the nerves within the periosteum or the nerves within the surrounding soft tissues and the nerves are irritated. Osteomyelitis is mainly due to bacterial infection in the bone marrow, which causes massive and repeated bacterial multiplication resulting in localized redness, swelling, heat and pain. When the inflammatory reaction is not obvious, there may be no clinical symptoms, but as the amount of bacteria increases over time, the toxicity gradually intensifies. When the bone marrow cavity is not able to contain the purulent material, it may ulcerate into the periosteum and surrounding soft tissues, resulting in significant redness, swelling, heat, pain, and limitation of movement. The most effective treatment for osteomyelitis is continuous irrigation or temporary placement of antibiotic bone cement, and surgery is the fundamental treatment for chronic osteomyelitis.