Although I am Turkish and I am not great at English, I will try my best to write properly and explain my problem clearly.
I am having repetetive pain just in my left armpit area, and especially at a particular spot. I put my finger on (I guess it's about 1cmx1cm area) the area and it's actually kind of painful to hold my finger on it, I can say.
The pain normally appears on some particular motions; when I stick my arm to my chest hard (like pushing it to my side) or when I do the reverse as in a "flying by wings" motion, pushing my arm laterally upward. These particular motions make the armpit quite painful so I don't do them not to make the healing process slow. The pain always heals completely in 2-3 days but when I start training at gym, unless I use very light weights, it immediately appears again in 1-2 days after gym. (pain doesn't appear while doing exercise..)
Well. This injury I had is obviously caused by my bodybuilding training. I had this injury 3rd times now; the first 2 was in my right armpit, now it's happening to my left armpit for the first time, which really made me mad!
My mother is a physiotherapist. She suspects it's because of the serratus anterior muscle. She claims that when I do workouts like "bench press" or "pec deck flys", the serratus anterior works too, so for her, that seem to be the most possible muscle which lies(continues) into my armpit...So she tells me not to workout those "pectoral" muscle moves for 2 weeks. But then when I start doing them after 2-3 weeks, the same thing happens if I work hard and increase the weights.
Personally, I worry that this armpit pain is caused by "triceps dips", because this time, I did that workout so hard and deep, I worry that I stretched my arms too much and triceps are quite close to armpit, don't you think this might be the cause also?
Oh, this is very long now, I doubt anyone ever would read it, but I post this message to this forum and another bodybuilding forum, so I hope someone will suggest some logical things at least...
PS: You can simply google the specific workouts I have mentioned in this post