Experiencing pain after surgery is normal and is often due to inflammation in the part of the body where surgery occurred. ​This type of pain is called acute post-surgical pain and is short-term, generally less than three months.​ However, 5-10% of patients who undergo major surgery develop chronic post-surgical pain, which is pain that persists past the normal healing process (generally longer than three months).   

Fibromyalgia is a lifelong condition characterized by widespread musculoskeletal pain. The pain may vary with time, move around the body, or change in intensity.

Sickle cell disease (SCD) is a genetic condition that causes red blood cells to become abnormally shaped. When their shape is abnormal, red blood cells have a more difficult time moving through blood vessels and carry oxygen. This can cause pain and other health problems. People with sickle cell disease may experience episodes of severe pain, fatigue, and organ damage. The disease is most common among people of African, Mediterranean, and Middle Eastern descent.