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Splenectomy, asplenia and splenic dysfunction

On this page

 - Background 
 - What does the spleen do? 
 - What you should do if you do not have a spleen 
 - Vaccinations
 - Further information


A splenectomy is an operation to remove the spleen. You may need a splenectomy if your spleen: 

  • doesn’t work properly 
  • has been affected by injury or disease, or 
  • is enlarged (swollen) and causing problems (for example, it is removing healthy red blood cells as well as old, damaged ones).  

Other terms which are used include:  

  • asplenia (no spleen), or
  • splenic dysfunction – when the spleen does not work properly.  

The spleen is a fist-sized organ in the upper left side of your abdomen, next to your stomach and behind your ribs.  

It's an important part of your immune system, but you can survive without it. This is because the liver can take over many of the spleen's functions. 

People who do not have a spleen, or who have a dysfunctional spleen, have an increased risk of developing severe infections such as pneumonia, septicaemia (blood poisoning) and meningitis. 

What does the spleen do?

The spleen has some important functions. 

  • It fights invading germs in the blood (the spleen contains white blood cells, which fight infection). 
  • It controls the level of blood cells (white blood cells, red blood cells and platelets). 
  • It filters the blood and removes any old or damaged red blood cells. 

What you should do if you do not have a spleen 

  • Make sure you have had all your routine immunisations (talk to your doctor or practice nurse, or visit NHS 111 Wales. (This is an external page and is not monitored by us.) 
  • People with asplenia or splenic dysfunction need some additional immunisations. Check with your GP, practice nurse or health visitor.  
  • Remind your doctor and dentist that you do not have a spleen. 
  • Take your medications as prescribed. 
  • If you think you have an infection you should contact a doctor immediately. Signs of infection may include a raised temperature, sore throat, unexplained cough, abdominal pain, headache with drowsiness, or a rash.  
  • Get medical attention if you are bitten by an animal. 
  • Protect yourself against malaria if you are travelling to countries where there is a risk of infection. 
  • Carry a card or wear a medical ID bracelet or necklace to alert other people in an emergency. 


Check with your GP surgery that you have had all your routine NHS vaccinations. 

You should also be vaccinated against the following:

Further information

You can find more information on vaccines, or the diseases they protect against, offered in Wales at: or 

If you have any questions or want more information, you can visit, talk to your doctor or nurse or call NHS 111 Wales. (This is an external page and is not monitored by us.)