Hello,
The various possibilities for popping,clicking joints are a cartilage tear or rotator cuff tear that is rubbing with the joint,arthrosis or degeneration of the joint and arthritis esp osteoarthritis and rheumatoid arthritis.
The exact cause can be found out only after x-ray or blood tests.Pls consult an orthopedician or rheumatologist for that.
Hope it helps.Take care and pls do keep me posted on how you are doing.
When I saw the Orthopedic specialist, he told me I needed an MRI to diagnose correctly, but I couldn't afford it at the time (still can't).
sounds familiar.....I have the same problem with my shoulders, and I'm not usre WHAT is wrong. And I am only 16. :)