Get intermittent water-balloon swelling just above right clavicle. can feel it coming on when i walk. makes me lightheaded?

AC Joint cyst: I have seen patients who present with swelling at the ac joint (where the collar bone meets the shoulder blade) that is intermittent with activity (such as walking). This is typically a cyst that is related to arthritis in that joint. You should be evaluated. I have no way of explaining lightheaded feelings related to this problem so evaluation would be helpful to you.