A lot of brown moles on the breast may be a physiological phenomenon caused by aging, and may also be caused by the proliferation of fibroids, seborrheic keratosis, and other reasons. 1. Physiological phenomenon: usually, with the increase of age, the pigmentation around the mammary glands will be aggravated, if there is no obvious pain and swelling, it does not need special treatment. Eating more vitamin-rich food in daily life can play a certain role. 2. Hyperplasia of fibroma: related to endocrine changes, mostly seen in the endocrine changes of estrogen, progesterone and prolactin, which will lead to hyperplasia of fibroma, manifested as hyperpigmentation and growth of brown moles. 3. Seborrheic keratosis: long brown spots may also be caused by seborrheic keratosis due to skin aging, sun exposure, also known as age spots, usually dark brown, not obvious, generally benign lesions. At the same time, brown moles found around the breast are associated with skin diseases and hyperpigmentation, and also need to be identified with spider nevi. If you have a lot of brown moles around your breasts, it is recommended that you go to a regular hospital and get a clear diagnosis and standardized treatment under the guidance of your doctor.