Painful vagina during intercourse is painful intercourse. There are several reasons for painful intercourse: 1. Inflammation of the vagina. If you have bacterial vaginitis, trichomonas vaginitis or mycotic vaginitis, it can easily lead to redness and swelling of the mucous membrane of the vaginal wall and itching of the vulva. During intercourse because of irritation so it can aggravate the swelling of the vaginal mucosa and cause painful intercourse. If the vagina is too dry, the vaginal secretions will decrease and cause pain during intercourse because the vagina is not expanded in time. If you are too tense and can’t relax, you may also have vaginal pain during intercourse.