Some people are born without a spleen or need to have it removed because of illness or injury.
The spleen is a fist-sized organ in the upper left side of your abdomen, next to your stomach and behind your left 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.
The spleen has some important functions:
If the spleen does not work properly, it may start to remove healthy blood cells.
This can lead to:
Spleen pain is usually felt as a pain behind your left ribs. It may be tender when you touch the area.
This can be a sign of a damaged, ruptured or enlarged spleen.
The spleen can become damaged or may burst (rupture) after an injury, such as a blow to the abdomen, a car accident, a sporting accident or broken ribs.
Rupture can happen straight away or it may happen weeks after the injury.
Signs of a ruptured spleen are:
Sometimes if you lie down and raise your legs, you can feel the pain at the tip of your left shoulder.
A ruptured spleen is a medical emergency, as it can cause life-threatening bleeding.
Go straight to A&E if you think you have ruptured or damaged your spleen.
An enlarged spleen does not always cause symptoms.
Otherwise, look out for:
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. You may be prescribed antibiotics 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's enlarged.
Surgery is only necessary if the enlarged spleen is causing serious complications or the cause cannot be found.
You may need an operation to remove your spleen, known as a splenectomy, if it's not working properly or it's damaged, diseased or enlarged.
Sometimes just part of your spleen can be removed, which is called a partial splenectomy.
If there's time, you'll be advised to have certain vaccinations before the operation. This is because spleen removal weakens your immune system and can make you more likely to get an infection.
Most operations to remove spleens are carried out using keyhole surgery (laparoscopy).
Keyhole spleen removal allows a surgeon to get inside your tummy (abdomen) to your spleen without having to make large cuts.
This means you'll have less scarring and may recover from the operation more quickly. But you'll still need a general anaesthetic.
The procedure involves:
The cuts are then stitched up or sometimes glued together.
You may be able to go home the same day, or you may need to stay in hospital overnight.
If you go home the same day, someone will need to stay with you for the first 24 hours.
Open surgery is where one large cut is made. It may be needed if your spleen is too large or too damaged to be removed using keyhole surgery. Often, in emergencies, this is the preferred method.
You'll need a general anaesthetic and may need to stay in hospital for a few days to recover.
It's normal to feel sore and be bruised after a splenectomy, but you'll be given pain relief.
You should be able to eat and drink as normal soon after the operation.
Like any operation, spleen removal carries a small risk of complications, including bleeding and infection.
Your doctor will talk through these risks with you.
You should be given breathing and leg exercises to do at home to reduce your risk of getting a blood clot or a chest infection.
Another risk is the surgical wound becoming infected. If you spot any signs of infection, contact your GP or hospital immediately, as you may need antibiotics.
Recovery usually takes a few weeks. Your doctor or nurse will advise when you can go back to your usual activities, such as driving.
If your spleen needs to be removed, other organs, such as the liver, can take over many of the spleen's functions.
This means you'll still be able to cope with most infections. But there's a small risk that a serious infection may develop quickly. This risk will be present for the rest of your life.
Young children have a higher risk of serious infection than adults, but the risk is still small.
This risk can be minimised by following simple precautions to prevent infection.
Check with your GP surgery that you have had all your routine childhood vaccinations.
You should also be vaccinated against:
It's recommended that you take low-dose antibiotics for the rest of your life to prevent bacterial infections.
Antibiotics are particularly important:
See a GP as soon as possible if you get signs of an infection.
Signs of infection include:
Your GP can prescribe a course of antibiotics for you to use if you get an infection.
If your infection becomes serious, you may be admitted to hospital.
Bites from animals and small blood-sucking parasites called ticks can cause infections.
If you get bitten by an animal, particularly a dog, start your course of antibiotics if you have them with you, and seek medical advice urgently.
If you go trekking or camping regularly, you may be at risk of Lyme disease, a 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.
Healthcare professionals will mark your health records to show that you do not have a working spleen.
But always remember to tell any medical professionals that you see, including your dentist.
It's a good idea to carry or wear some medical ID.
If you need help or emergency treatment, your medical ID will alert staff to your condition.
If you're travelling abroad:
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 cannot avoid them, speak to a GP or local pharmacist about antimalarial medicine before you travel.
You should also use mosquito nets and insect repellent.