Black holes are points in space that are so dense they create deep gravity sinks. Beyond a certain region, not even light can escape the powerful tug of a black hole's gravity. And anything that v ...

An STD is an infection that you get from someone else by having sex. You can get an STD by having vaginal sex (penis in the vagina), anal sex (penis in the rectum), or oral sex (penis in the mouth ...

The viruses, bacteria, and parasites that cause sexually transmitted infections (STIs) have different incubation periods, or timeframes between when they are passed on and when symptoms appear. Some ...