The spleen is a fist-sized organ found in the upper left side of your abdomen, behind your stomach and left ribs.
Some people are born without a spleen or need to have it removed because of disease or injury.
It's an important part of your immune system but you can survive without it, as the liver can take over many of the spleen's functions.
What does the spleen do?
The spleen has a few important functions:
- it fights any invading germs in the blood (the spleen contains infection-fighting white blood cells)
- it controls the level of white blood cells, red blood cells and platelets (platelets are small cells that form blood clots)
- it screens the blood and removes any old or damaged red blood cells
If the spleen doesn't work properly:
- the malfunctioning spleen may start to remove healthy blood cells as well as abnormal blood cells, reducing the number of healthy cells in your blood:
– a reduced red blood cell count can lead to anaemia
– a reduced white blood cell count increases your risk of infection
– a reduced platelet count can cause bleeding or bruising
- it may trap too many platelets and become clogged with excess red blood cells and platelets
If the spleen needs to be removed, other organs such as the liver can take over many of the spleen's functions.
This means people without a spleen will still be able to cope with most infections, although there is a small risk that a serious infection may develop quickly – see What are the risks of not having a spleen?
When does the spleen need to be removed?
An operation to remove the spleen, known as a splenectomy, may be needed if the spleen is damaged, diseased or enlarged.
Damaged or ruptured spleen
The spleen can become damaged or may rupture (burst) after a forceful blow to the abdomen.
Rupture can happen straight away or it may happen weeks after the injury.
Signs of a ruptured spleen are:
- pain behind your left ribs and tenderness when you touch this area
- dizziness and a rapid heart rate (a sign of low blood pressure caused by blood loss)
A ruptured spleen is a medical emergency, as it can cause life-threatening bleeding. Go straight to your nearest hospital’s accident and emergency (A&E) department if you think you've ruptured or damaged your spleen.
Most at risk are children and adults with infections, people with diseases that affect the liver and spleen, and people who live in areas where malaria is a problem.
An enlarged spleen doesn't always cause symptoms. Otherwise, look out for:
- feeling full very quickly after eating (an enlarged spleen can press on the stomach)
- feeling discomfort or pain on the upper left side of the abdomen (seek medical help immediately if this is severe or gets worse quickly)
- anaemia and/or fatigue
- frequent infections
- easy bleeding
The spleen is not usually removed if it's just enlarged. Instead, you'll receive treatment for any underlying condition and your spleen will be monitored. Antibiotics may be prescribed if there's an infection. You'll need to avoid contact sports for a while, as you'll be at greater risk of rupturing the spleen while it is enlarged.
Surgery is only necessary if the enlarged spleen is causing serious complications or if the cause can't be found.
What does a splenectomy involve?
If there's time, you'll be advised to have a series of immunisations before the operation.
Most splenectomies are carried out using a laparoscopy (keyhole surgery). This is a minimally invasive type of surgical procedure that allows a surgeon to access the inside of your abdomen without having to make large incisions in your skin.
Open surgery, where a larger incision is made, may be needed if the spleen is too large or too damaged to be removed via keyhole surgery.
Read information about having an operation.
It's normal to feel sore and be bruised after a splenectomy, but you'll be given pain relief medication. You may need to stay in hospital for a few days before you can go home.
Like any operation, a splenectomy carries a small risk of complications, including bleeding and infection. Your doctor will run through these risks with you, and explain the procedure in detail.
What are the risks of not having a spleen?
If you don’t have a working spleen, you can still cope with most infections, as the spleen is only one part of your immune system. However, there is a small risk that an infection can quickly become serious. This risk will be present for the rest of your life.
Young children have a higher risk than adults, but the risk is still small. The risk is also increased if you have a medical condition such as sickle cell anaemia, coeliac disease or a condition that affects your immune system, such as HIV.
This risk can be minimised by following simple precautions.
How can this risk of infection be minimised?
Make sure you have had all your routine childhood vaccinations. You should also be vaccinated against:
- pneumococcal infections such as pneumonia, with regular boosters at least every five years
- flu (get the seasonal flu jab every autumn)
- Haemophilus influenzae type b (Hib)
- meningitis C (MenC)
It's recommended that you take low-dose antibiotics for the rest of your life to prevent bacterial infections. Antibiotics are particularly important:
- for children under the age of 16
- for the first two years after your spleen is removed (splenectomy)
- if your immune system doesn't work properly
Watch out for infection
Watch out for signs of infection, such as:
- high temperature (fever)
- sore throat
- severe headache
- headache with drowsiness or a rash
- abdominal pain
Your doctor can prescribe a course of antibiotics for you to use if you get an infection. Start taking them at the first sign of an infection and see your doctor as soon as possible.
If your infection becomes serious, you will be admitted to hospital.
Animal and tick bites
Bites from animals and ticks (small blood-sucking parasites) can cause infections.
If you get bitten by an animal, particularly a dog, start your course of antibiotics and seek medical advice urgently.
If you go trekking or camping regularly, you may be at risk of babesiosis, which is a rare disease transmitted by ticks. Try to avoid tick bites by wearing clothes that cover your skin, particularly long trousers. If you become ill, get medical advice straight away.
Tell medical staff about your condition
Healthcare professionals will mark your health records to show that you don't have a working spleen. However, always remember to tell any medical professionals that you consult, including your dentist.
Carry medical ID
It's a good idea to carry or wear some medical ID. For example:
- if your spleen is removed, the hospital may give you a splenectomy card to take home with you
- you may want to buy your own medical ID, such as a MedicAlert or Medi-Tag bracelet or pendant
If you need help or emergency treatment, your medical ID will alert the staff to your condition.
If you're travelling abroad:
- you may be advised to take a course of antibiotics with you
- find out if you need an extra meningitis vaccination (types ACWY)
- check if you need any travel vaccinations
People without a working spleen have an increased risk of developing a severe form of malaria. If possible, avoid countries where malaria is present. If you can't, speak to your doctor or local pharmacist about anti-malaria medicine before you travel. You should also use mosquito nets and insect repellent.