Inquiring minds want to know!
Dear Dr. Eva,
Please don’t laugh at me, this is a serious question. I’m a straight woman. I was in a women’s internet chat room where we were discussing whether women have “one hole or two” – that is, does urine drain through the vagina, or from a separate opening? Some people thought urine comes out through the vagina; others said women have a separate hole to drain urine. I always thought that in women urine drains through the vagina, the same way that sperm and urine come out through the same opening in men. Also, isn’t the bladder connection to the vagina the reason why it’s so common for women to get bladder infections after having sex? Now you may say “just look at yourself” – well, I tried that, but it’s not that easy to see and it’s not all that clear to me. Please help out.
Dear Enquiring Mind,
Good for you for not being too embarrassed to write in with this question. Your logic is very reasonable, but you’re incorrect. This is one of those situations where a picture is worth a thousand words, so here it is:
Notice that the model’s pubic area is shaved, which can be very itchy but does make the anatomy a lot easier to see. You can see in the photo that the woman’s urethra (the opening for urine) is very small, much smaller than a man’s. The urethra is located just a few millimeters above the vagina, but not inside it. You can see how friction during sex can push bacteria from the anal area into the urethra, causing bladder infections. Women’s urethras are also very short, less than 1/10 the length of the male urethra. Bacteria that get washed out with the next urination in men, can get into the bladder and cause infection in women. I don’t mean to be sacrilegious, but the placement of the female urethra does seem to be a design flaw that evolution hasn’t corrected yet, like the lower back and the knee joint.
The location of the urethra also explains why it is possible to test for vaginal gonorrhea and chlamydia infections with just a urine sample and no pelvic exam: the urethra and the vagina are so close together that if there is a vaginal infection, the urine will pick up traces of it.
In older women, after menopause, the vaginal tissues become thinner and smaller because of the lack of estrogen. In elderly women, after shrinkage of the vaginal walls, sometimes the urethra does end up located just inside the vagina.
So this isn’t quite as simple a question as it seems. And you’re not the only one who sometimes has trouble seeing where things are. In hospitals and nursing homes, sometimes a catheter (drain) intended to be placed in the bladder does not drain urine because it was accidentally placed in the vagina. Even professionals sometimes have difficulty finding women’s urethras.
Eva Hersh is a Baltimore family physician. Send your comments and questions to her by email at firstname.lastname@example.org.