Hi Doctor? What health hazard is there in sucking a penis which has STD? thanks

The health hazard is that you can get whatever disease your sex partner is infected with. I assume you are talking about performing fellatio on someone who has an STD [sexually-transmitted disease] that particularly affects the penis, such as gonorrhea, which causes a discharge from the penis. Gonorrhea and chlamydia can cause infection in your throat if your partner is infected; there may not always be symptoms or they may seem like something else. There have been conflicting and confusing reports on the possibility of acquiring HIV through performing fellatio on a man who has the virus. There have been some reported cases, but there is always the possibility that some men did not want to admit they'd been the "bottom" in anal sex. Unprotected anal intercourse is still overwhelmingly the main way gay men get HIV. (Although rare, "tops" can also get HIV if they have sex with an infected person and don't use a condom.)

Don't panic. If you know that you've had sex with a person who has an STD go to a health clinic where your anonymity will be respected, and get tested. Most STDs can be easily treated with antibiotics and you'll be fine, and can't pass along an STD to anyone else. Even HIV, although not curable as such, can be treated.

Don't delay. You'll be okay. You may not have caught anything but if you have, getting tested for an STD is the smartest thing you can do.

Let me know if you have any more questions.