What are the harms of fellatio to the body

Patient's question:

The attachment is a bit painful

Doctor's answer:

There are more sexually transmitted diseases transmitted through oral sex, including gonorrhea, genital herpes, genital warts, and syphilis, etc. However, the prerequisite is that the other half must be a sex patient. If both parties are healthy and have not been tested for reproductive system diseases or oral diseases, it should not affect health.