The pain of coitus is related to the following diseases: first, because of the local inflammation of the vagina, resulting in congestion and edema of the mucous membrane tissue. Friction during intercourse will aggravate this congestion and edema, so it will cause local pain. This patient will often be manifested as an increase in vaginal secretions, yellow color, or a local burning sensation in the vagina; second, vaginal secretions are relatively small, such as ovarian failure or endocrine disorders caused by a decrease in estradiol, may lead to a decrease in vaginal secretions, then the friction of coitus will lead to localized pain; third, coitus is relatively tense, resulting in vaginal contraction, which can also be painful. Thirdly, the relative tension during coitus can cause vaginal contraction, which can also cause pain, so it is best to go to the hospital to rule out inflammation and premature ovarian failure, and then intervene and treat according to the results.