After sex body aches and pains in more reasons, the more common is sex life lasts too long or too strenuous, may be due to suffer from related infectious diseases, suffering from lumbar muscle strain and other muscle strain can also lead to muscle aches and pains, female patients may also be due to suffer from related gynecological diseases, such as chronic pelvic inflammatory disease, and so on. 1. Sexual life lasts a long time, too strenuous: especially for people who usually do not exercise, in sexual life due to the action is too strenuous, and lasts for a long time, will produce more lactic acid, and in the muscle tissue of lactic acid buildup is too much, resulting in muscle aches and pains. 2. Infectious diseases: Sex due to not pay attention to warm or cold after sex, can lead to bacteria or viruses and other pathogenic microorganisms infected organisms, the patient may appear body aches and pain in the systemic infection symptoms. 3. Muscle strain: For patients who usually have muscle strain, when having sex, due to strenuous exercise, can also lead to muscle strain soreness. 4. Gynecological diseases: If women experience body aches and pains after sex, it may also be caused by gynecological diseases, such as chronic pelvic inflammatory disease and endometriosis.