The hazards of wearing tight underwear for women include the following: I. Skin diseases: If you wear tight and narrow underwear for a long time, you will not only feel uncomfortable, but if you wear it for a long time, there will not be enough expansion space between the skin and the outside world for normal gas exchange, resulting in blocked skin pores, pigmentation and causing skin diseases. Second, increase the risk of breast cancer: more serious is the greater the elasticity, the tighter the underwear will compress the breast tissue, affecting the blood circulation in and around the breast, which in turn increases the risk of breast cancer. Affecting lymphatic flow: slowing down the metabolism and increasing the toxins in the breast alveoli, which will increase the chance of disease. Breast nodules: When the breasts are squeezed by too tight underwear, the breast tissue will be congested and when toxins cannot be discharged from the breasts, small breast nodules will be formed.