An enlarged spleen. Spleno- (spleen) -megaly (mega - big)

Causes of splenomegaly range from infective (active or chronic infections, including such bugs as tuberculosis, malaria and kala azar) to hematological/haematological (e.g. myelofibrosis) to neoplastic to splenic vein thrombosis to portal hypertension.

Splenomegaly may be symptomless but is always pathological and, unless a cause is already known, is usually an indication for further investigation.

Clinically, a spleen is palpable in a normal sized patient once it enlarges to three times its normal size.