Whether it is normal for a 20-year-old girl to have brown breasts depends on the specific situation. Since the breasts of 20-year-old girls are generally the same color as their skin, it is normal for brown-skinned girls to have brown breasts; if the skin color of the whole body is not brown, but only the breasts are brown, first of all, we should exclude the problem of discoloration of intimate clothing, as well as the nipples and areolas being brown. In addition to the above factors, the overall breast is rarely brown, if only localized brown changes in the breast, consider the changes caused by breast bruising, breast disease or drug factors. 1, breast bruising: through tight, inappropriate underwear, may cause breast congestion, brown changes. If the areola and clothing friction too much may also produce pigmentation, so that the breast is brown. Choosing the right size, skin-friendly underwear can reduce these conditions. In addition, if there is a bump and other trauma to the breast area, brown bruising can also occur, you can apply hot compresses to promote blood circulation to relieve, usually a few days to eliminate; 2, breast disease: if the skin is brown bruising, may indicate that the lupus erythematosus, this performance can also occur in the breast area. In addition, if the skin of the breast is brown and orange peel-like changes occur, it often suggests breast cancer. In addition, flat warts, often multiple raised lesions, may appear on the breast area, also appearing brown in color. These cases need to go to the hospital for a clear diagnosis and targeted treatment; 3, drug factors: if the breast allergic diseases, such as eczema, dermatitis, etc., long-term application of hormonal creams can also make the surrounding skin pigmentation, so that the breast drug parts appear brown; 4, other causes: breast bites by mosquitoes or long acne, if there is a break can also appear brown marks, this situation is mostly pigmentation This situation is mostly caused by pigmentation. In addition to the above, 20-year-old girls also need to pay attention to the state of the areola, nipples, usually brown for the normal situation, is the normal secretion of hormones caused by pigmentation, and genetically related. However, if there is an abnormal enlargement of the nipples and areolas, a sudden deepening of the color, as well as menstrual disorders, abnormal bleeding and other accompanying symptoms, you need to go to the hospital for a clear diagnosis of hormonal secretion abnormalities or diseases.