1. Infections: Splenomegaly can be caused by various infections such as mononucleosis, malaria, tuberculosis, and bacterial endocarditis.
2. Liver diseases: Liver diseases such as cirrhosis, hepatitis, and portal hypertension can lead to splenomegaly due to increased pressure in the portal vein.
3. Blood disorders: Conditions like leukemia, lymphoma, and hemolytic anemia can cause the spleen to enlarge as it works harder to filter abnormal or damaged blood cells.
4. Autoimmune disorders: Autoimmune diseases like lupus, rheumatoid arthritis, and sarcoidosis can trigger inflammation in the spleen, leading to enlargement.
5. Congestive heart failure: In cases of congestive heart failure, the heart may not be able to pump blood effectively, causing a backup of blood in the veins and leading to splenomegaly.