text: i am a 48 year old black male.i have constant muscle and joint pain with popping of the joints.healthy male?   rheumatoid arthritis is an autoimmune disorder that causes stiffness and pain in the joints. osteoarthritis involves growth of bone spurs and degeneration of cartilage at a joint. it is very common in adults older than 45 and can cause joint pain.  joint pain may also be caused by bursitis (inflammation of the bursae). the bursae are fluid-filled sacs that cushion and pad bony prominences, allowing muscles and tendons to move freely over the bone.  common causes    unusual exertion or overuse, including strains or sprains  injury, including fracture  gout (especially found in the big toe)  osteoarthritis  septic arthritis  tendonitis  bursitis  infectious diseases, including  influenza  measles (rubeola)  rheumatic fever  epstein-barr viral syndrome  hepatitis  mumps  rubella (german measles)  varicella (chickenpox)  chondromalacia patellae  osteomyelitis  autoimmune diseases such as rheumatoid arthritis and lupus