Blue veins on breast & one goin through nipples.. they get sore from time to time! what does this mean..?

Hmm: There is a condition called mondor's disease. This is a painful condition caused by a thrombophlebitis ( blood clot ) of a vein on the breast. It is benign and self limiting. You mention soreness, well it could be... Are you breast feeding, felt any lumps in the breast/arm pit? See you obgyn or a surgeon. Do not neglect!

Growing pains: Breast enlargement either by augmentation or hormonal stimulation can result in enlarged, tender veins in the reticular dermis. They are treatable by a specialist.