Is a bump on your armpit bad?

It is most likely a lymph node. It is your body's defense against something in the body that shouldn't be there, such as a virus. Leave it alone and it should you away in about a week. If you get them on your under arm or, near or on your breast, it could be a sign of Breast cancer, if so, get examined by a doctor. But overall, they are normal, just don't mess with it and it will go away.

It might also be an ingrown hair. If you are skilled enough with a tweezer, try to pinch out the top, of the hair. be careful, because if the tweezer its dirty, it could get infected and get worse. If you can't get it out, then wait or go to a doctor if it's really bothering you.