Since the spleen must deal with this overproduction it may become enlarged. Infections, such as mononucleosis , that enlarge lymph nodes also affect the spleen. In some instances mononucleosis has caused the spleen to enlarge so much that it bursts. Because it is well supplied with blood , a ruptured spleen can produce anemia if it loses blood slowly or shock if it loses blood rapidly. A ruptured spleen from an accident, such as an automobile accident, can result in death sometimes when it seems that one has recovered from the effects of the accident.
Emergency surgery is needed to correct the problems caused by a ruptured spleen.
Other diseases that result in enlargement of the spleen include brucellosis , cirrhosis of the liver , rheumatoid arthritis , typhoid fever , malaria , syphilis , and some types of anemia. For the most part an enlarged spleen in these diseases is more important as a diagnostic tool than it is a danger to the patient. An overactive spleen is blamed for the disease thrombocytopenia, in which there are too few platelets to cause blood clotting.