Your spleen is an organ located just below your left rib cage. Many conditions — including infections, liver disease and some cancers — can cause an enlarged spleen, also known as splenomegaly (spleh-no-MEG-uh-lee).
An enlarged spleen usually doesn't cause symptoms. It's often discovered during a routine physical exam. Your doctor generally can't feel a normal-sized spleen in adults but can feel an enlarged spleen. Your doctor will likely request imaging and blood tests to help identify the cause.
Treatment for an enlarged spleen focuses on the underlying condition that's causing it. Surgically removing an enlarged spleen isn't usually the first treatment, but is sometimes recommended.
An enlarged spleen may cause:
- No symptoms in some cases
- Pain or fullness in the left upper abdomen that may spread to the left shoulder
- Feeling full without eating or after eating only a small amount from the enlarged spleen pressing on your stomach
- Frequent infections
- Easy bleeding
When to see a doctor
See your doctor promptly if you have pain in your left upper abdomen, especially if it's severe or the pain gets worse when you take a deep breath.
A number of infections and diseases may cause an enlarged spleen. The enlargement of the spleen may be temporary, depending on treatment. Contributing factors include:
- Viral infections, such as mononucleosis
- Bacterial infections, such as syphilis or an infection of your heart's inner lining (endocarditis)
- Parasitic infections, such as malaria
- Cirrhosis and other diseases affecting the liver
- Various types of hemolytic anemia — a condition characterized by early destruction of red blood cells
- Blood cancers, such as leukemia and myeloproliferative neoplasms, and lymphomas, such as Hodgkin's disease
- Metabolic disorders, such as Gaucher's disease and Niemann-Pick disease
- Pressure on the veins in the spleen or liver or a blood clot in these veins
How the spleen works
Your spleen is tucked under your rib cage next to your stomach on the left side of your abdomen. It's a soft, spongy organ that performs several critical jobs. Your spleen:
- Filters out and destroys old, damaged blood cells
- Prevents infection by producing white blood cells (lymphocytes) and acting as a first line of defense against disease-causing organisms
- Stores red blood cells and platelets, which help your blood clot
An enlarged spleen affects each of these vital functions. As your spleen grows larger, it filters normal red blood cells as well as abnormal ones, reducing the number of healthy cells in your bloodstream. It also traps too many platelets.
Excess red blood cells and platelets eventually can clog your spleen and affect normal functioning. An enlarged spleen may even outgrow its own blood supply, which can damage or destroy sections of the organ.
Anyone can develop an enlarged spleen at any age, but certain groups are at higher risk, including:
- Children and young adults with infections, such as mononucleosis
- People who have Gaucher's disease, Niemann-Pick disease, and several other inherited metabolic disorders affecting the liver and spleen
- People who live in or travel to areas where malaria is common
Potential complications of an enlarged spleen are:
- Infection. An enlarged spleen can reduce the number of healthy red blood cells, platelets and white cells in your bloodstream, leading to more frequent infections. Anemia and increased bleeding also are possible.
- Ruptured spleen. Even healthy spleens are soft and easily damaged, especially in car crashes. The possibility of rupture is much greater when your spleen is enlarged. A ruptured spleen can cause life-threatening bleeding into your abdominal cavity.