a woman with malaise

There’s a saying to the effect that sex is like pizza: Even when it’s bad, it’s good. One notable exception, however, may be when you start feeling nauseous after sex. Instead of basking in the afterglow, you’re staring at the ceiling, wishing the room would stop spinning and worrying you might actually throw up on your partner. Or possibly on yourself. In either case, it’s not a good feeling. Nor is feeling nauseous after sex "normal" per se, according to Dr. Adeeti Gupta, an OB/Gyn in Manhattan (via Refinery29). But, yes, it can happen — and not just to women, but to all genders, according to Dr. Shirin Lakhani, a UK-based intimate health specialist (via Marie Claire).

There are a variety of reasons why you might feel nauseous after sex, but one thing on which you may rest assured is that post coital nausea is a sign of neither pregnancy nor miscarriage. Although nausea may be associated with early pregnancy, it takes at least a number of days following conception for the pregnancy hormone, human chorionic gonadotropin, to reach a high enough level so as to cause nausea (per the Mayo Clinic). And in order for a miscarriage to take place, there has to first be implantation of the embryo into the uterine wall (via USC Fertility). And that process takes a number of days as well, according to UCSF Health. So, let’s take a look at what it actually might be.

Nausea after sex could be a sign of dehydration

man in bed reaching for glass of water

"The human body is about 70 percent water," explains Paula Burke, clinical dietitian at MetroSouth Medical Center in Blue Island (via Chicago Tribune). Since all of the bodily systems use and/or lose water as they function, your water volume must constantly be replenished (via the Mayo Clinic). And the Mayo Clinic defines dehydration as being in any state of deficit with regard to water replenishment, all the way from the mildest to the most severe. Although severe dehydration is more likely to put one in imminent danger, even mild dehydration can make you feel off, or even "rotten," as Financial Review puts it. Accordingly, if you find yourself feeling nauseous after sex, perhaps the first thing you should ask yourself is whether dehydration might be your "Occam’s razor" (i.e., the best explanation because it’s the simplest), according to Marie Claire.

So, how much should you be drinking to avoid dehydration-related nausea after sex? The CDC doesn’t offer a specific recommendation with regard to what level of fluid intake constitutes optimal hydration because it varies too much among individuals. However, CDC epidemiologist, Dr. Alyson Goodman suggests that for most adults, it’s most likely somewhere in the vicinity of four 8-ounce glasses of water per day (via Chicago Tribune). Nevertheless, 43% of all adults surveyed by the CDC in 2013 reported drinking less than that, with 36% drinking just one to three glasses per day.

a woman in bed folds her arms over her eyes
a doctor reads x ray films
photo from From Here To Eternity