Splenomegaly is an enlargement of the spleen beyond its normal size.

The spleen is an organ involved in the production and maintenance of red blood cells, the production of certain circulating white blood cells, and is a part of the lymph system and the immune system.

Because of its wide variety of functions, the spleen may be affected by many conditions involving the blood or lymph system, and by infection, malignancies, liver disease, and parasites.

• Infections
  • Infectious mononucleosis (EBV or CMV)
  • Other viral infections
  • Parasitic infections
  • Cat scratch disease
  • Bacterial infections
• Diseases involving the liver
  • Cirrhosis (portal vein obstruction, portal hypertension)
  • Sclerosing cholangitis
  • Wilson's disease
  • Biliary atresia
  • Cystic fibrosis
• Hemolytic anemias
  • Thalassemia
  • Hemoglobinopathies
  • Hemolytic anemia due to G6PD deficiency
  • Idiopathic autoimmune hemolytic anemia
  • Immune hemolytic anemia
• Cancer
  • Leukemia
  • Lymphoma
  • Hodgkin's disease
• Other causes
  • Sarcoidosis
  • Sickle cell splenic crisis
  • Banti's syndrome
  • Felty syndrome

Rupture of the enlarged spleen is particularly possible in infectious mononucleosis and several other causes of splenomegaly. Appropriate limitation of activity, including avoiding contact sports, will help prevent trauma that might cause the spleen to rupture.

Care will be required for the specific condition causing the splenomegaly. Follow the instructions given by your health care provider regarding appropriate care.

Although often there are no symptoms from an enlarged spleen, you may experience pain in the left upper section of your abdomen. If you do, especially if it is severe or gets worse when you take a deep breath, you should seek attention from your doctor right away.

Other symptoms that you may experience and warrant a call or visit to your doctor depend on the underlying cause of the enlarged spleen. Refer to articles of topics mentioned in the Causes section above for additional information.

The physician will ask a series of questions to determine if you have symptoms either from the enlarged spleen or the underlying cause of the large spleen, such as fever or signs of an infectious disease.

The doctor will also perform a thorough exam of your abdomen. To check for an enlarged spleen, he or she will percuss (tap) along the left upper quadrant of your abdomen and palpate (feel) in that same area, especially just under the rib cage.

Diagnostic tests may be required, including:

• Blood tests such as a CBC
• Tests for suspected causes
• Abdominal film or CT scan