What causes a swollen spleen, and will it ever return to its normal size?

Splenomegally: Enlarged spleen can be associated with various conditions: various anemias, connective tissue disease, infections, lymphoma, mononucleosis.

Many causes: It may have many causes such as infections, inflammatory diseases ,trauma, a cyst, a large abscess, or Infiltrative diseases. It's important to seek treatment for the cause of your enlarged spleen. Left untreated, an enlarged spleen may lead to serious complications. Visit a gastroenterologist as soon as possible!