What Could Cause Appearance Of Knots Under The Arm Pit?

hi i am a 21 year old male... and since i was 15 or younger i will get knotes under my arm pit every time i move ... its almost always the right side thats gets a huge one and the left side gets a very small one for like not even a hole day and disappears.. and its usley after i drink alot of tea,pop and eat alot of candy...can this be from to much caffeine and surger ?(sorry bad spelling)