The yellowing of clothes under the armpits may be related to sweat stains or armpit odor, taking certain medications and other factors. 1. Eating a lot of yellow food, such as citrus, carrots, pumpkin and other foods, which are rich in carotene, is likely to cause a small amount of yellow pigment in the sweat, resulting in a short-term situation of yellowing of underarm clothes after sweating. 2. The yellowing of clothes under the armpits may be the cause of armpit odor. The sweat glands in the armpits secrete a lot of sweat, which is fermented and decomposed with bacteria, and yellow sweat can be formed, and there is a certain degree of heredity in this situation. 3. In addition, there are patients with sweat with color, may be directly related to the drugs taken, such as riboflavin, rifampicin and so on. After stopping these drugs, the yellowing of clothes under the armpits will be reduced naturally. It is recommended that patients pay attention to hygiene in daily life, diligent bathing, diligent change of clothing, if the situation continues to be unrelieved, timely to the regular hospital.