The white solid on women’s underwear is mostly caused by vaginal secretions flowing onto the underwear, which may be a physiological manifestation or may be caused by disease. For women with normal ovarian endocrine secretion, the ovaries secrete estrogen and progesterone periodically. Therefore, under the influence of estrogen and progesterone, it will cause the cells in the vagina to shed and gather to become leucorrhea, which will stay on the underwear after it flows out, thus it may lead to the appearance of obvious white solids. For example, during ovulation or the luteal phase, this discharge will increase significantly, but at this time women will not have vulvar itching symptoms or other abnormalities, which is why it is called a physiological manifestation. However, some women may have beanbag-like leucorrhea due to mycosis fungoides, when the beanbag-like leucorrhea stays on their underwear and also forms white particles, but such women will have obvious vulvar itching as well as burning and tingling symptoms.