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
• Anemia
• Fatigue
• Frequent infections
• Easy bleeding

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

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.