First Aid for Jellyfish Sting

By Bill, posted
Jellyfish are freeswimming marine animals with trailing tentacles, used as a method of defence, and to trap their prey. Humans through their marine activities can sometimes make contact with the jellyfish’s tentacles and receive a nasty sting. This can range from an itch to a life threatening allergic reaction. Ignoring first aid myths and applying a simple treatment protocol could help alleviate the symptoms of a sting.


There are more than 2000 types of jellyfish in the world's oceans, most being harmless but not all. Here are a few venomous varieties to look out for:

Lion’s Mane Jellyfish - Northern Atlantic, Arctic & Northern Pacific 

Portuguese Man of War - Atlantic & Indian Ocean

Box Jellyfish - Tropical Indo Pacific (can spread to any warmer waters)

Irukandji Jellyfish - Northern Australia

Did you know - The Irukandji jellyfish measures a microscopic 5 mm (0.2 inches). Yet it arguably has the most venomous animal toxin on the planet. One to avoid!

Just Been Stung

Being stung by a jellyfish can cause the onset of  panic and fear. Also the casualty can suffer with mild to excruciating pain across the affected area. It can help to offer reassurance to the casualty, and to check to see if a lifeguard is on duty nearby.

Helpful hint - Lifeguards are always first aid trained and as part of their training they should have good knowledge of jellyfish stings.


It is the tentacles on the jellyfish that can cause the most harm to humans when we encroach on their habitat. The Jellyfish’s tentacles have stinging cells (nematocysts) which can wrap around the limbs of a person, or slash across the face and other areas of the body. This can cause any of the below symptoms:
  • Intense stinging / burning pain
  • Itchy rash
  • Skin welts (raised itchy rash)
Sometimes the jellyfish sting can be identified by the distinctive tentacle like imprints left on the skin.


The treatment protocol should be initiated quickly and be kept simple. Take control and avoid being distracted by other bystanders. Particularly regarding old wives tales such as urinating on the affected area. There are some simple steps you can take to help alleviate pain for the casualty:
  1. Rinse the affected area thoroughly with seawater
  2. Soak the affected area in hot water for 20-30 minutes (hot enough to just about be comfortable)
  3. Use hot flannels or towels if it is not possible to soak the affected area e.g. the face
  4. Offer reassurance to the casualty
True fact - The jellyfish’s stinging cells rely on a certain chemical makeup (incl. saltwater). Any change to this makeup could reactivate the stinging process and cause further pain. Hence why the stinging cells should be rinsed off with saltwater.

Further Help

Visit a minor injury unit if:
  • The pain is intense and will not go away
  • The casualty has been stung in the face or genitals 
Visit A&E or dial 999 / 112 if the casualty displays any of the below symptoms:
  • Breathing difficulties
  • Chest pain
  • Seizures
  • Unconsciousness 
Helpful hint - Jellyfish stings can often occur whilst on holiday and in sometimes exotic locations. Always know the number for the emergency services when travelling to any foreign country.

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