The feeling of swelling in the lower body may be caused by physiological reasons, such as menstruation or pregnancy; or pathological reasons, such as pelvic infection, uterine fibroids and so on. 1. Physiological reasons: some women may experience discomfort during menstruation due to an increase in prostaglandins, which can lead to swelling in the lower body. Meanwhile, during pregnancy, the enlargement of the uterus can also lead to discomfort such as lower body swelling. 2. Pathological reasons: when women have pelvic infections, urinary tract infections, vaginal infections, due to the stimulation of inflammation, may lead to lower body swelling. In addition, when suffering from uterine fibroids, uterine adenomyosis and other more serious diseases, may also lead to lower body swelling and other discomfort. There may be other reasons for women to experience lower body swelling, and they need to go to the hospital for timely examination and consultation to promote relief.