If the female urethral opening is red and swollen, then the possible causes: 1, urethral infection, which can appear local mucosal red and swollen changes, accompanied by local pain, acute inflammation can even be accompanied by the urethral opening mucosa appears erosion, oozing blood and other symptoms. This is due to the infection of surrounding colonized bacteria, such as Staphylococcus aureus, Escherichia coli, etc. 2, urethral caruncle, seen in the urethral mucosa prolapse and then the formation of caruncle or polyp-like changes, long-term friction or physical stimulation, urine stimulation, etc., can produce local redness and swelling and other changes. The appearance of small sarcoma-like protrusions, larger, and even block the urethral orifice and affect the patient’s urination, it is mostly related to ageing or estrogen loss. 3, unclean sexual contact leads to related pathogenic infections, such as gonococcal infection, mycoplasma infection, chlamydia infection, etc., can appear urethral orifice redness and swelling, accompanied by increased local discharge. The urethral orifice can be seen as yellow or white mucous-like discharge, and can be accompanied by related urination symptoms.