There are several reasons for the vague pain on the left side of the female triangle: First, it may be because of gynecological inflammation, such as common cervicitis, endometritis, pelvic inflammatory disease, vaginitis, ovarian inflammatory disease or vulvodynia, because when women suffer from these gynecological inflammatory diseases, inflammation can lead to increased permeability of the skin mucosa and blood vessels at the lesion site, stimulating the sensory nerves at the lesion site, which will cause the left side of the triangle The hidden pain. Secondly, for women over 40 years old, if they have hidden pain in the triangle, it may be due to gynecological tumors, such as common cervical tumors, endometriomas, pelvic tumors, vaginal tumors, ovarian tumors or tubal tumors, etc. When women suffer from these gynecological tumors, the tumors can compress and destroy the tissue cells in normal areas, which can also cause hidden pain in the left side of the female triangle.