Splenomegaly
Splenomegaly means enlargement of the spleen. While in the adult the spleen cannot be felt unless it is enlarged by some sort of disease process, in the neonate and infant it may just protrude beneath the ribs on the left. Splenomegaly due to disease has many different causes, with the most common depending on the part of the world concerned. In the tropics it is usually due to infections such as malaria or schistosomiasis - the increased demands on the body's defences causes the white pulp of the spleen to enlarge in order to meet the demand. In the Mediterranean it may be due to thalassaemia (see blood and circulation in the chest cavity section). In the Western world, splenomegaly in the young may be due to infection (by the Epstein Barr virus, for example, responsible for glandular fever), to blood related Cancers such as leukaemia (see blood and circulation in the chest cavity section) or other blood conditions such as hereditary spherocytosis. Rarely it is secondary to cirrhotic liver disease (see disorders of the liver in the digestive tract section). This increases pressure in the veins running from the spleen and causes it to enlarge. Besides being uncomfortable, and at risk of rupture (which is why teenagers with glandular fever are warned off contact sports) an enlarged spleen also causes complications of its own, since it may remove too many red blood cells, resulting in anaemia, and too many platelets, producing problems with blood clotting.
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