Firm, rubbery lump directly under the nipple or areola
Tenderness or soreness in the nipple/chest area
Swelling or puffiness around one or both nipples
Enlarged breast tissue that feels more like gland than fat
Nipple sensitivity or pain when touched
Uneven chest shape or one side larger than the other
Breast tissue that persists despite weight loss
Possible nipple discharge in some cases
Symptoms that develop during puberty, steroid use, or certain medications
A doctor can confirm it by exam and, if needed, tests