Jellyfish and other sea creature stings


If you or someone else has been stung in the sea, get help from someone with first aid training, such as a lifeguard.

Further medical assistance may be needed if the symptoms of a sting are severe and very painful.

Some people may have a severe allergic reaction after being stung, known as anaphylaxis or anaphylactic shock, which can sometimes be fatal.

Any adverse allergic reaction should be treated as a medical emergency. Dial 999 to request an ambulance.

Weever fish

A sting from a weever fish can cause:

A more serious reaction to a weever fish sting may lead to:

  • an abnormal heart rhythm (arrhythmia)
  • shortness of breath 
  • weakness
  • paralysis 
  • seizures (fits)
  • a drop in blood pressure
  • episodes of unconsciousness

Although weever fish stings are usually very painful, serious reactions are uncommon and deaths are extremely rare.

Seek immediate medical assistance if you or someone else has been stung by a weever fish. Any spines left in the foot need to be carefully removed.


A stingray's sharp barb can leave a jagged cut or puncture wound in the flesh, and the venom from the sting can cause pain and swelling.

Other symptoms may include:

Deaths from stingray injuries are rare, but there have been cases where people have died following a puncture wound to the heart or abdomen.

Always seek immediate medical assistance if you or someone else has been stung by a stingray. Alert a lifeguard, if there is one nearby, before dialling 999 to request an ambulance.

A stingray sting should be dealt with at the accident and emergency (A&E) department of the nearest hospital.

Find your nearest A&E department.

Sea urchins

A puncture wound from a sea urchin can be painful and cause inflammation and redness around the affected area.

If you have puncture wounds in several places, you may experience more severe symptoms, including:

  • tiredness
  • weakness
  • aching muscles
  • shock
  • respiratory failure
  • paralysis

In rare cases, people have died from severe sea urchin injuries.

Get immediate medical attention if your symptoms include:

  • breathing problems
  • chest pain
  • signs of infection, such as increased redness and swelling in the affected area and a high temperature (fever) of 38C (100.4F) or above

Medical assistance is also required if there are spines in or near a joint, as they may need to be surgically removed.


If you're stung by a jellyfish, you'll feel severe pain immediately and develop an itchy rash and welts (raised, circular areas on the skin) where the tentacles have touched you.

Other symptoms may include:

  • nausea or vomiting
  • diarrhoea
  • abdominal pain
  • muscle spasms
  • numbness or tingling
  • swollen lymph nodes (the small nodules found in several places around the body, including the groin and armpit)

In rare cases, a serious reaction to a jellyfish sting can result in breathing difficulties, coma or even death.

If you or someone else has been stung by a jellyfish, seek immediate medical assistance by dialling 999 if you or they:

  • are having problems breathing or swallowing
  • have chest pain
  • have severe pain at the site of the sting
  • are very young or elderly
  • have a sting that affects a large area of the body
  • have been stung on the face or genitals
  • have severe pain, itchiness or swelling around the sting

Portuguese man-of-war

A Portuguese man-of-war sting may cause a red line with small, white lesions. In severe cases, blisters and welts (raised, circular areas of skin) may also appear. 

A sting from a Portuguese man-of-war can sometimes cause a severe allergic reaction, although deaths as a result of a sting are rare.

After a sting, seek medical attention if:

  • the pain is severe and lasts more than an hour
  • the rash gets worse
  • there are signs of infection, such as increased redness and swelling in the affected area and a high temperature (fever) of 38C (100.4F) or above

Read more about how sea creature stings are treated.

Page last reviewed: 05/05/2015
Next review due: 01/05/2018