Crepitus...crackling joints

When I walk around in the morning, my joints sound like popcorn popping. Am I normal? Many people have some degree of crepitus, a crackling or grinding sound made when uneven cartilage surfaces rub against each other. It usually occurs in large joints, like the knee or shoulder. Crepitus is different from the loud snap you hear when you crack a knuckle: That's caused by nitrogen bubbles inside the joints popping under pressure, says Raymond Rocco Monto, M.D., an orthopedic surgeon and spokesman for the American Academy of Orthopaedic Surgeons. If you feel pain along with the popping (especially while climbing stairs, squatting or kneeling), see an orthopedist. It could be a sign of injury or arthritis. Yes, you heard us right: Arthritis has become more common in young athletic women who got hurt playing sports as adolescents, Dr. Monto says.

http://www.womenshealthmag.com/health/health-questions-answered?page=2