###Human: What can be done when blood occurs in semen after having unprotected sex? ###Assistant: Hello. Blood in semen with no other symptoms is very likely idiopathic or no pathology. After a period of abstinence sometimes aggressive frequent sexual activity leads to hematospermia. Majority of times it is self-limiting. Unprotected sexual intercourse will not give rise to this (rather it causes urethritis). Seminal vesicle can occasionally be infected from the blood. Just once examination by surgeon or urologist to feel seminal vesicle per rectum is preferred. For the present episode, wait for some time that it will resolve on its own.