Spots on a woman’s underwear may be unwashed, or there may be abnormal vaginal discharge or bleeding. It is considered to be caused by ovulation, and may also be caused by other diseases such as cervicitis, vulvovaginal pseudomyxomatosis, and endometriosis. 1. Unwashed:If the patient’s underwear has not been worn for a long time or is not usually washed, it will lead to moldy underwear, which will result in mildew and lead to spotting of the patient’s underwear. 2. Ovulation:When a woman is ovulating, the leukorrhea will increase and be thin, and some women will also experience a small amount of bleeding. Leukorrhea or blood sticking to the panties will cause spots on the panties. 3. Vulvovaginal pseudomycosis: Vulvovaginal pseudomycosis is caused by pseudomycosis infection, and the main symptoms of the patient are vulvar itching, increased vaginal discharge in the form of curd, and painful intercourse. Increased vaginal discharge can also lead to spotting in the patient’s underwear. 4. Other: endometriosis, trichomonas vaginitis, bacterial vaginitis and other diseases can also lead to an increase in vaginal discharge or bleeding phenomenon, which will lead to spots in the patient’s underwear. When spots appear in a woman’s underwear, they may be caused by unwashed or ovulation and do not need to be treated. It can also be caused by diseases, and patients should seek medical attention to identify the cause of the disease and follow the doctor’s instructions for treatment.