Hi
Welcome to the forum!
I agree with SurgiMenopause in that it is difficult t give a confirmed diagnosis on net. We can only give suggestions which may be off the mark as we depend only on the details of the post. However a number of times we also manage to give a correct diagnosis. The idea is to help you to understand what all you should be aware of and what all investigations should be done with your kind of symptoms. It is only to help reach a diagnosis and not to diagnose.
Nipple pain at your age could be due to rough sex if you are sexually active, eczema, contact dermatitis, bacterial or fungal infection. If there is breast enlargement then it could be due to gynecomastia.
I think you should discuss these possibilities with your doctor. It is difficult to comment beyond this without examining.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
Scratch that first statement! Oops! I'm sorry, Doctorneemedical! There is a professional on this particular forum. I was mixed up as to which forum I was on and meant to say it was a forum for non-professionals, not doctors (but I was mixed up).
This is a forum for non-professional doctors. It is really impossible to diagnose over the internet as well. Could be anything from a heart valve defect to gastrointestinal tract problem to chest wall muscle inflammation to breast cancer (rare but still happens in men). It is worth going to a competent licensed medical doctor about.