Question
Almost all of my joints (shoulders, wrists, knees, ankles, and sometimes elbows) crack and pop excessively.  The main problem though is my shoulders.  I can't do any type of overhead press (dips, upright rows, and incline bench can also hurt).  If I do, my shoulders will pop loudly on almost every rep.  I'm 17 and I've lifted weights for maybe 3-4 years now.  I do mostly powerlifting and olympic weightlifting (except for the jerk, because of the overhead pressing problem). I try to do rotational work for my shoulders for injury prevention, but my workouts are still very limited, due to my shoulders' ability to handle certain exercises.  What can I do to get healthier shoulders?  
Thanks! I appreciate it.

Answer
If you have overdeveloped your chest muscles in relation to your back and posterior shoulder muscles, your shoulders may be rotated more forward and inward.  This can cause an 'impingement syndrome" where the rotator cuff tendons get pinched between the humerus and the acromion process of the scapula, especially with overhead use of the arms.  I think I would have your shoulders evaluated by a sports chiropractor or ortho surgeon. I would like an xray of each to evaluate the shape of the acromion process for impingement.  You may have to avoid overhead movements for awhile if you are experiencing chronic tendon also.  Physical therapy procedures and stretching can help improve your condition. I also adjust the shoulder joints as a chiropractor to improve the range of motion in the joints, this helps a lot.  First thing is to get them evaluated!