White blood cells produced in the spleen engulf bacteria, dead tissue, and foreign matter, removing them from the blood as blood passes through it. The spleen also maintains healthy red and white blood cells and platelets; platelets help your blood clot. The spleen filters blood, removing abnormal blood cells from the bloodstream. A spleen is normally about the size of a fist. A doctor usually can't feel it during an examination, but diseases can cause it to swell and become many times its normal size. Because the spleen is involved in many functions, many conditions may affect it.

An enlarged spleen is not always a sign of a problem. When a spleen becomes enlarged, though, it often means it has been doing its job but has become overactive. For example, sometimes the spleen is overactive in removing and destroying blood cells. It can happen for many reasons, including problems with too many platelets and other disorders of the blood. Followings are the symptoms of enlarged spleen:

1. A feeling of being full when no food has been eaten or after consuming only a little amount – can occur when an enlarged spleen presses up against the stomach.
2. Fullness or pain in the upper abdomen on the left side that may migrate to the shoulder on the left side.
3. In specific cases there are no symptoms
4. Fatigue
5. Anemia
6. Easy bleeding
7. Frequent infections