HomeHealth TopicEnvironmental

10 Do's and Don’ts for Treating a Jellyfish Sting

Jill L. Jaimes, MDKatie E. Golden, MD
Written by Jill L. Jaimes, MD | Reviewed by Katie E. Golden, MD
Published on August 2, 2022

Key takeaways:

  • There are many species of jellyfish, but only a few are harmful to humans. Most stings cause only mild symptoms.

  • If a jellyfish stings you, there are several easy steps you can take to treat the sting at home.

  • Jellyfish stings can cause serious reactions, but they're rare. Seek immediate medical attention if your symptoms feel more severe than just skin irritation — like having difficulty breathing or feeling faint.

A cropped shot of someone picking up a jellyfish on the beach.
Julie Wright-Gonzales/iStock via Getty Images

Cnidaria are a group of sea creatures that sting. Jellyfish, Portuguese man-of-war, sea wasps, and sea anemones all belong to this group. There are over 10,000 cnidaria species, but most of them are not harmful to humans. In this group, jellyfish stings are the most common. They account for 150 million stings every year. 

Jellyfish like to hang out in warm, coastal waters. So that’s where most stings occur. Their tentacles have stingers called “nematocysts,” hollow tubes that release venom when they touch human skin. 

The symptoms of a sting are usually mild. But jellyfish stings can be more severe depending on the species as well as the size and number of stings. So here’s what to do (and avoid) if it happens to you.  

Symptoms of a sting 

In many cases you won’t see a jellyfish before it stings you. So you may not realize it until the symptoms start. The symptoms of a sting depend on the type and size of the jellyfish. 

Mild symptoms can last a few hours to a few days. They include:

  • Pain immediately after contact with the jellyfish 

  • Redness where the sting occurred, which usually appears as red lines from the tentacles

  • Swelling — or blisters — around the red areas

  • Itching at the site of the sting 

Multiple or larger stings can cause more significant symptoms. These symptoms generally start right away, or within 30 minutes of a sting. They can include:

  • Muscle cramps

  • Abdominal pain

  • Nausea and vomiting

  • Diarrhea

Symptoms that are even more severe are rare — but they’re still possible. This is more likely with a sting by the Australian box jellyfish — also known as the sea wasp or Chironex fleckeri. These jellyfish can deliver deadly stings. They live in Australia and off the coast of the Philippines, Malaysia, and Japan. 

But severe stings can still happen with other jellyfish species, especially if they sting you multiple times. The symptoms of a life-threatening sting include:

  • Seizures: This can occur because jellyfish venom can affect the nervous system. 

  • Low blood pressure: This can make you feel weak, lightheaded, or cause you to pass out.

  • Anaphylaxis: This occurs as a severe allergy to the jellyfish venom. Symptoms may include trouble breathing or swelling of the lips, tongue, or throat. 

  • Cardiac arrest: There have been reports of cardiac arrest as a rare complication of an Australian box jellyfish sting.

How to treat a jellyfish sting at home

If a jellyfish stings you, the first thing to do is stay calm. This can be easier said than done when the pain takes you by surprise. But once you get the chance to collect your thoughts, there are several things you can do to treat the symptoms of a jellyfish sting.

There’s a lot of debate among experts about the best way to care for a jellyfish sting. This is because there’s not much scientific evidence on the topic. And different jellyfish stings react differently to treatment. 

Taking all of these differing opinions into account, here are the top five tips for jellyfish sting treatment:

  1. Rinse the skin with seawater. This will help clean it and remove additional stingers. But it’s much better to use seawater instead of fresh water. This is because freshwater can further activate nematocysts, which releases more venom. 

  2. Remove visible stingers. It’s best to wear gloves to remove tentacles and stingers to avoid further stings. And some experts warn against using tweezers because it risks releasing more venom.

  3. Apply baking soda. If you have access to baking soda, a slurry of baking soda and seawater can help remove any remaining stingers. 

  4. Apply hot water for pain relief. There’s an ongoing debate about whether hot or cold water can help with pain relief. In a combined review of research, hot water came out on top as more helpful for pain relief. 

  5. Use over-the-counter pain and itch relief. For most stings, ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) can help with the pain. And if you’re experiencing itchiness or swelling, medications like diphenhydramine (Benadryl) can also help.

Jellyfish sting remedies to avoid

There are a few easy mistakes people make when caring for a jellyfish sting. It’s important to avoid these five things:

  1. Freshwater: Freshwater can worsen the venom release and make your symptoms worse.

  2. Rubbing alcohol: When treating injuries to the skin, rubbing alcohol can often act as an antiseptic and keep the area clean. But with some jellyfish species, the alcohol can cause the release of more venom.

  3. Vinegar: There’s a lot of debate among experts as to whether vinegar is helpful or harmful for jellyfish stings. Some evidence suggests that vinegar can inactivate venom and decrease pain with some stings. But the problem is that this is not true for all jellyfish species. For some species, it may worsen the pain. So it’s best to avoid vinegar.

  4. Compression bandages: Try to leave the area as open as possible after the sting. If you need to cover it to protect it, use a light and loosely placed bandage. The pressure from a tight bandage can release venom from stingers that have not yet discharged. 

  5. Urine: It’s a myth that peeing on a jellyfish sting helps with pain relief. 

When to seek medical attention for a jellyfish sting

Some jellyfish species are more likely to cause severe reactions — like the Chironex fleckeri (sea wasp) mentioned above, or multiple stings from a man-of-war. In these cases, you may need immediate medical attention. 

You should go to the emergency room if you have:

  • Trouble breathing

  • Lightheadedness or loss of consciousness

  • Extreme fatigue or trouble staying awake

  • Swelling of the lips, mouth, tongue, or throat

  • Severe pain

  • Palpitations, or a sensation that your heart is beating fast or abnormally 

  • Seizures

Tips to prevent a jellyfish sting

When you head to the beach, a few prevention tips can help make sure you have an enjoyable time. It can help to:

  • Pay attention to local news and any signs on the beach about increased jellyfish numbers or stings.

  • Consider wearing a wetsuit to protect against jellyfish stings.

  • Use protective lotions that are formulated to act like the mucus of clownfish. Because clownfish live with sea anemones, they have a coating that protects them from stings. These lotions are not 100% effective, but they help reduce the number and severity of stings.

The bottom line

Most jellyfish stings cause only mild symptoms. Even so, it’s best to prepare and know what to do if you get stung. In areas that have more jellyfish, protective swimsuits will help keep you safe from stings. 

For most stings in the U.S., the best thing to do is remove any remaining stingers, rinse the area with salt water, and apply hot water to help with pain. And if you experience more severe symptoms, go to the nearest emergency room for treatment. 

References

Brinkman, D. L., et al. (2012). Venom proteome of the box jellyfish Chironex fleckeri. PLoS One.

Cegolon, L., et al. (2013). Jellyfish stings and their management: A review. Marine Drugs.

View All References (6)

Hornbeak, K. B., et al. (2017). Marine envenomation. Emergency Medicine Clinics of North America.

Lakkis, N. A., et al. (2015). Jellyfish stings: A practical approach. Wilderness & Environmental Medicine

Montgomery, L., et al. (2016). To pee, or not to pee: A review on envenomation and treatment in European jellyfish species. Marine drugs

Staggs, R., et al. (2022). Cnidaria toxicity. StatPearls.

Ward, N. T., et al. (2012). Evidence-based treatment of jellyfish stings in North America and Hawaii. Annals of Emergency Medicine.



GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.

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