I searched it up and its just your breast growing, the ball underneath your nipple is called a breast bud. You could be nearing your time (as in period) I'm 12 and I have that on one nipple, so don't worry. You are just developing into a woman. Or if you are really concerned, see a doctor or ask your mum, or anyone close to you. I hope this helped.
There are at least three kinds of things that could cause a lump in your breast. (You said in your nipple -- I'm answering as if you mean in your breast in the nipple area. I hope that's helpful, but if not, maybe someone else has an answer.)
1. A fibrous cyst. This is a very common, benign (non-cancerous) condition. 2. A tumor, which could be benign or malignant (cancer). 3. Or, if you're nursing a baby these days, you could have a plugged duct.
I've had #1 and #3 and both times was scared it was cancer. Doctors helped sort it all out.
If you're nursing and it's a plugged duct, heat and some strong suction (from a breast pump or a baby, or if those don't work, an adult volunteer) can help break it up, which you should do as soon as possible so it doesn't turn into a breast infection (mastitis -- treatable but no fun at all).
If it's not a plugged duct and the lump has been there a little while (like two weeks), I'd check with a doctor. They'll know what to do to distinguish the benign possibilities from cancer. And if it is cancer, earlier treatment gives you a much better chance to survive.
You don't say weather you are male or female! In any case it could be very serious get to a Doctor, If you are male believe it or not breast cancer is just as common in men as it is in women when a man gets a lump all the more reason to get to a Doctor! If you are female the same don't take any chanches it also could be just a swollen gland if you are near that time of the month, but still don't take a chance, if it is very sore or tender it is more likly a gland, and lump under the skin that you can't see to determin what it is needs medical attention!!..Genaveve
