Darkening of the areola may be caused by discomfort with underwear, pregnancy, overstimulation and so on. 1. Underwear discomfort: If the underwear you wear on a daily basis is made of rough material, it will constantly rub against the areola, which may lead to melanin precipitation and darkening of the areola. 2. Pregnancy: After pregnancy, the hormone level of the body will change, and the estrogen and progesterone in the body will increase, which will make the lotion nipple larger, and also make the nipple and areola black. 3. Excessive stimulation: If excessive sexual life or constant exfoliation of the, may lead to melanin precipitation, the areola blackened. The darkening of the areola should also be considered as a result of abnormal hormone secretion, and it is recommended that the patient go to the hospital for examination when there are uncomfortable symptoms.