Blood disorders
Conditions that directly affect the blood will cause the spleen to enlarge. Naturally, the spleen enlarges when it has to filter the blood flowing in the body, therefore, any illness or disease that destroys the red blood cells and causes the spleen to work harder to filter the blood will cause the spleen to become larger. For example, hemolytic anemia [3] which causes red blood cells to become hemolyzed (broken down) will make the spleen larger. Other blood related disorders like thalassemia [4] and sickle cell that cause the red blood cells to become misshapen will be damaged when these cells are squeezed through the capillaries. This leads to the spleen working harder to remove these damaged red blood cells leading to enlargement.