Hey I have researched this and it is only puberty!!! You guys have nothing to worry about.
ok i am 22 now. i remember when i was 12 or 13 going through puberty i had this problem. Nipples sensitive to movement or agitation. i am going through this problem again but for a longer duration. i have noticed that there has been a gradual decrease to my current problem.
my best guess is that it has to do with the hormones in the body, testosterone and estrogen. A person goes through phases where these hormones increase and decrees production in the body: early, middle, and late adolescence. at these times the hormones are not in the usual proportion and the body reflects the differences. as with the case of sore nipples with no swelling probably have to do with estrogen and a mild form of gynocomastia. This condition most of the time occurs with steroid use, probably caused by the different mix of hormones in the body (steroids increase testosterone production). So in essence the body is not use to the loss or gain of hormones and the body reacts to this difference (kinda like drug withdrawal symptoms).
it should be noted that i took strong anti-biotics and it really messed my body up. I have been going through a variety of minor health ailments and im getting sick of it. Maybe the anti-biotics caused a change of hormones? Not sure.
Also there are steroids in common medicines like asthma medication that can affect the hormones.
I am not a doctor, medical student, or anything like that. Just making suppositions
Learn to spell you sound uneducated! Pain* because* just*