Mental Floss has a blurb about this that I found interesting. Here are a couple of excerpts.
Take Your Aspirin
Hereâ€™s the secret they donâ€™t tell you about space travel: It hurts. Spacesickness is common, particularly for first-timers and anybody who launches into a bunch of fancy spins or soaring across the station before theyâ€™ve had time to get acclimatized. And trust us, hurling in zero-G is no fun. Worse, the effects of weightlessness can really do a number on your body. One symptom is lower back pain, caused by your spine stretching as the fluid within it floats. You get taller, but you also get achier. Headaches are another major issue. Without gravity, itâ€™s harder for your heart to do its job. Blood pressure drops and your blood doesnâ€™t reach your feet as reliably. Instead, it flows to your head, turning your face puffy and red and giving you a headache, just as if youâ€™d been hanging upside down on the monkeybars.
Donâ€™t Ask, Donâ€™t Tell
Thatâ€™s the official NASA stance on whether anyoneâ€™s ever had sex in space. We may never know for certain whether astronauts and/or their international peers are hooking it up up there, but we do know that, if they were, it would come with some less-than-sexy challenges. For one thing, thereâ€™s no natural convection in zero gravity, so any heat you work up stays with you. At the same time, however, you also tend to sweat more in zero G, making outer space sex both hotter and wetter than that on Earthâ€”and not in a good way. Another problem is that, in zero G, you naturally push away from anything you touch. That means anybody wanting to have sex in space would probably need to be strapped down and strapped together. Oh, and that drop in blood pressure we already mentioned? That would have dire effects on male â€œegosâ€ galaxy wide.
I am still interested. I think that it would be so very cool to go into space. It is one of my all time dreams to do so.