Urinating On Jellyfish Sting

Stupid Question ™
June 7, 2004
By John Ruch
© 2004

Q: Is it true that urinating on a jellyfish sting alleviates the discomfort? If so, who figured that out?
—Anonymous, from the Internet


A: At best, urinating on a jellyfish sting will do nothing. Experiments indicate that in some jellyfish species, urine actually sets off the remaining stinging cells, making the sting even worse.

The urine cure and other folk remedies miss the mark, anyway. The point of rinsing the wounded area is not to alleviate the pain. The venom’s already in you. Urinating on it will not help any more than it does to urinate on your thumb after you hit it with a hammer.

The point of the rinse is to get rid of any remaining tentacles or other jellyfish tissue that might still harbor stinging cells, or nematocysts, which could still fire and make the sting worse. (These cells, which are all over jellyfish, contain a tiny poison dart that shoots out at a touch or because of a chemical reaction; thousands of them typically fire simultaneously.) For the aforementioned reason, urine is a terrible candidate for the job.

Susan Scott, “Oceanwatch” columnist for the Honolulu Star-Bulletin, has investigated jellyfish stings in the field (as well as in the lab) probably as much as anyone, having spent years visiting injured tourists and the like on Hawaii’s beaches. A registered nurse, she and husband Dr. Craig Thomas authored “All Stings Considered: First Aid and Medical Treatment of Hawai’i’s Marine Injuries.”

In her column in 2001, Scott summed up years of study on a variety of sting “cures”: “Nothing worked.” In an e-mail to me, she summed it up another way: “Anything works.”

This paradox goes to the heart of the urine myth. “Nothing worked” means that none of the main folk remedies—including urine, meat tenderizer and commercial sprays—did anything to stop the pain of a sting.

On the other hand, “Anything works,” because the vast majority of jellyfish stings are not severe and their effects disappear within a few hours at most, no matter whether you urinate on yourself or simply do nothing.

“Anything works for another reason”—mind over matter. “The placebo effect is a powerful treatment,” Scott said, referring to the common psychological phenomenon in which people who receive a useless treatment feel better simply because they think they have been medicated. In this case, believing you have been given an analgesic may well reduce your subjective experience of pain. (In addition, different people can have widely varying pain thresholds.)

Folk remedies for jellyfish stings can be quite exotic; Scott mentioned mustard, and minor studies have been done on Coca-Cola. But the urine cure is exceptionally widespread, found on beaches from Vietnam to Belize. It is also applied (equally uselessly) to other marine wounds, like coral cuts and sea urchin spike punctures. How did the idea get started?

Urine is an ancient folk medicine for a boggling variety of ills, and its main nitrous component, urea, does have some real medicinal properties (though not for jellyfish stings). Among many other things, it’s also a folk remedy for bee stings.

Scott had a simple conjecture for its application to jellyfish: “We think this is because it’s usually the only substance readily handy during jellyfish stings.”

The “anything/nothing works” warning aside, there are definitely things you should do to treat a jellyfish sting, and there are things you can do to prevent it from becoming worse. (The following information focuses on box jellies and Portuguese man-of-wars, which are the most dangerous jellyfish on bathing beaches; check with lifeguards at your beach for guidance on identifying local dangerous species.)

In all cases, immediately scrape off any remaining tentacles or other visible jellyfish tissue with a glove or some kind of tool—never with bare hands.
On box jellies, you can rinse the area with vinegar. Experiments have shown that vinegar chemically deactivates the nematocysts of box jellies, disabling any remaining cells from firing into your skin.

On Portuguese man-of-war stings, do not use vinegar; experiments show that in its species, vinegar sets off the nematocysts. Instead, just rinse the area with seawater. (Fresh water is probably OK, too, though some doctors worry it can also set off nematocysts by osmosis.)

Once the area is clear of any more nematocysts, you can attempt to deal with the pain. Gritting your teeth works. Scott said hot or cold packs, or hot baths, are the only treatments she’s seen work for anybody.

If the pain is severe and lasting, or there are any other symptoms such as sweating or faintness, go to an emergency room immediately. Some jellyfish are certainly capable of killing humans, and some people are highly allergic to minor stings.

If you touched the area with your hands before rinsing, make sure you wash up before touching yourself anywhere else, especially your eyes. An eyeful of nematocysts is unpleasant indeed.