While it's common to get a little too high every now and then, getting seriously ill is another issue. According to The Huffington Post , a mysterious marijuana-related illness has been on the rise — particularly in states where marijuana has been legalized. The condition, known as cannabinoid hyperemesis syndrome (or CHS), is accompanied by symptoms such as vomiting, severe abdominal pain, and nausea — even though marijuana is often used to combat nausea. It's also linked to heavy marijuana use over long periods of time. And strangely, symptoms can be relieved with hot showers or baths, though doctors are unsure why. "It is certainly something that, before legalization, we almost never saw," Kennon Heard, MD, PhD, told CBS . "Now we are seeing it quite frequently." As CBS reports, the condition can even cause dehydration and kidney failure, though it's usually resolved within days after someone stops using marijuana. However, since CHS has really only begun to be recognized as an illness within the last decade, it's still hard to tell exactly how many people have suffered from it and exactly what causes it. It can also be difficult to diagnose, since patients might not want to tell their doctors about drug use. Dr. Heard told the Denver Channel in December that he had a theory that those who use marijuana heavily may "have changes in the receptors in their body, and those receptors become disregulated in some way, and it starts causing pain," but there is yet to be conclusive evidence. All of this, then, backs up the idea that we still don't know as much about marijuana that we should — and that it may be a good idea to invest in making research a little easier