Jellyfish stings are common problems if you swim or dive in seawater. The stings vary from mild to severe. Common signs and symptoms include burning pain, red tracks on the skin, itchiness, swelling, tingling and numbness or even throbbing pain radiates up a leg or arm. Some jellyfish stings, Australian box jellyfish in particular, can be life threating. Call emergency services or go to see a doctor if you are stung on the face, mouth, eyes or genitalia, or the area of sting is large, or you have severe symptoms like dizziness, difficulties in breathing and heart problem.
Luckily, most of the jellyfish stings are mild. Remove jellyfish tentacles immediately to prevent continued release of venom. They can be brushed off by using a plastic object like credit card or substance like shaving cream. Avoid vigorous rubbing. Wash the wound with seawater to decrease discomfort. Take painkillers to relieve pain.
For stings in tropical waters, especially those due to Hawaiian box jellyfish or bluebottle jellyfish, should be treated with hot water immersion.
Prevention is the most important as jellyfish stings can be lethal. Do not enter water during jellyfish season or wearing clothing or suits that provide mechanical barrier to stings if you have to swim in waters with jellyfish.