A fishy odor after a woman’s period is usually caused by vaginitis. After menstruation, vaginal secretions sometimes have a bloody or sour odor, but not a fishy odor. If the vaginal discharge has a distinct fishy odor at this time, it is usually caused by vaginal inflammation. During menstruation, women’s vaginal resistance is relatively low, coupled with a certain degree of change in the vaginal environment, prone to flora imbalance. If the vagina is infected with pathogenic microorganisms such as Haemophilus vaginalis, Trichomonas, or anaerobic bacteria, the phenomenon of vaginal discharge with a fishy odor often occurs. Some women do not pay attention to menstrual hygiene, such as not changing tampons or sanitary napkins for a long time can also easily lead to vaginitis. It is recommended that if you find any abnormality, you should consult a doctor for examination and symptomatic treatment.