The common reasons why women do not bleed in small amounts during menstruation are the following: 1. It may be because of gynecological inflammation, such as common vaginitis, endometritis, pelvic inflammatory disease and tubal inflammation, etc. When women suffer from these gynecological inflammatory diseases, the permeability of the skin mucosa in the areas suffering from inflammation will increase, and at the same time, the permeability of the small blood vessels and capillaries in these areas will also increase, and the inflammatory substances will The inflammatory material will destroy the structure of capillaries, thus causing blood to easily leak or flow out from the vessels, which can lead to a small or even large amount of bleeding not during menstruation. 2. For older women, such as those over 40 years old, it is important to suspect whether there are tumor diseases, such as common endometrial cancer, uterine cancer, ovarian plasmacytoma and vaginal rhabdomyosarcoma, etc. These tumors can also compress These tumors can also compress or even destroy small blood vessels, which can also lead to bleeding without menstruation.