Your spleen is an organ located just below your rib cage on your left side. A number of conditions — from infections to liver disease and some cancers — can cause an enlarged spleen, also known as splenomegaly (spleh-no-MEG-uh-lee).
Most people don’t have symptoms with an enlarged spleen. The problem is often discovered during a routine physical exam. Your doctor can’t feel a normal-sized spleen in adults — unless you’re very slender — but can feel an enlarged spleen. If you have an enlarged spleen, your doctor will likely request imaging and blood tests to help identify the cause.
Treatment for an enlarged spleen focuses on relieving the underlying condition. Surgically removing an enlarged spleen isn’t usually the first treatment, but it may be recommended in certain situations.
A number of infections and diseases can contribute to an enlarged spleen. The effects on your spleen may be only temporary, depending on how well your treatment works. 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 premature destruction of red blood cells
- Blood cancers, such as leukemia, 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 and can be easily damaged. Among other things, your spleen:
- Filters out and destroys old and damaged blood cells
- Plays a key role in preventing infection by producing white blood cells called lymphocytes and acting as a first line of defense against invading pathogens
- Stores red blood cells and platelets, the cells that help your blood clot
An enlarged spleen affects each of these vital functions. For instance, as your spleen grows larger, it begins to filter normal red blood cells as well as abnormal ones, reducing the number of healthy cells in your bloodstream. It also traps too many platelets. Eventually, excess red blood cells and platelets can clog your spleen, interfering with its normal functioning. An enlarged spleen may even outgrow its own blood supply, which can damage or destroy sections of the organ.
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 — this can occur when an enlarged spleen presses 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.