Question: Will urine relieve the pain of a jellyfish sting?
Answer: Not really. Depending on the urine, it could even make it worse.
Jellyfish cause stinging by leaving nematocysts behind when they are touched. Nematocysts are tiny coiled stingers that, once triggered, inject venom into a victim. The amount and type of venom depends on the type of jellyfish, number of nematocysts, area of bare skin, and the thickness of the skin. There is often a tentacle or two left behind after a sting as well, covered with nematocysts.
The trick to treating pain of a jellyfish sting is to remove the nematocysts without triggering them to inject venom. Pressure triggers them, as well as fresh water and some chemicals.
Remove any tentacles
Use sand or a towel to remove the tentacles without touching them. Touching them with your bare hands will result in additional stings.
Rinse away the sting area to remove nematocysts
Here's where opinions differ. Ammonia, vinegar, vodka, denatured alcohol, water, urine and many other substances have all been touted as the cure for jellyfish stings.
A word of caution about vinegar: Studies suggest that vinegar actually worsens the pain of Portuguese Man of War, bluebottle, and other Physalia stings. These creatures are dangerous look-alikes to jellyfish. Vinegar has been shown to cause nearly 30% of Physalia nematocysts to fire.
Which brings us to urine. Urine consists of water and waste products of the body's blood stream, which includes ammonia -- the reason for its legendary use. Depending on the person -- and whether he or she is dehydrated, diabetic, on a protein diet, or dealing with myriad other conditions -- urine may or may not be about as good as fresh water. In fact, urine contains so much fresh water that stranded folks can drink their own urine to survive (don't worry, I'm cringing at the idea, too). Since we know fresh water will often make nematocysts fire, the logical conclusion is that urine will do the same thing.
Urine has about a 50/50 track record on the Internet. Many anonymous bloggers sing the praises of this readily available wonder tonic, but research just hasn't supported the claims. Others tell stories of urine not working at all. I've yet to read any supposed first-hand claims that urine made the pain of a jellyfish sting worse.
More About Jellyfish
Jellyfish venom can do more than cause pain; it can also cause anaphylaxis, a severe allergic reaction. Watch the victim for rash, hives, itching, shortness of breath, and swelling. If you suspect an allergic reaction, call 911 immediately, or get the victim to a hospital.
Pain from jellyfish stings can last anywhere from a few minutes to several days or even weeks. Nonsteroidal anti-inflammatory drugs (NSAIDS) can be used for pain. Unfortunately, the only sure-fire treatment is time.
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Buddin, Elizabeth. "Jellyfish." Unk publish date. Sea Science. South Carolina Department of Natural Resources. Retrieved 23 Oct 2007
Fenner, P.J., et al."First aid treatment of jellyfish stings in Australia. Response to a newly differentiated species." Medical Journal of Australia. 5 Apr 1995 PMID: 8469205
O'Reilly, G.M., et al."Prospective study of jellyfish stings from tropical Australia, including the major box jellyfish Chironex fleckeri." Medical Journal of Australia. 3 Dec 2001 PMID: 11837877