The spleen is located on the left side of the abdominal cavity just below the diaphragm. One of its main functions is to filter out all the harmful, infection-causing organisms from blood. Besides, it removes the old red blood cells from the bloodstream and decomposes them. It also acts like a blood reservoir by supplying additional blood to the body as and when required. Swollen spleen is also known as splenomegaly. It occurs when there is an increase in the workload of the organ.

Causes
One of the most common causes of the enlargement of this organ is infections caused by bacteria, viruses, or parasites.
It may get swollen due to some traumatic injury or inflammatory diseases such as rheumatoid arthritis.
It can happen when the liver is not working properly due to some diseases like liver cirrhosis.
It may be triggered by some blood diseases or abnormality in the lymph system.
In some cases, it is a symptom of some type of cancer like leukemia that affects the blood cells or lymphoma that affects the lymph tissue.

Symptoms
-- As the spleen swells and is stretched out, a pain is felt in the upper abdominal region.
-- A typical pain symptom is that it tends to get extended up to the left shoulder.
-- At times, the pain can be so severe that the patient may find it difficult to breathe properly.
-- In this condition, one experiences a sense of fullness all the time. As a result, the patient is unable to eat large meals, and he loses a lot of weight suddenly.
-- When abnormal functioning of this organ takes place due to swelling, an imbalance occurs in between the red and white blood cells.
-- This affects the clotting of blood, and the patient may suffer a huge blood loss even in small injuries.
-- Some worse symptoms are frequent infections, fatigues, jaundice, Anemia, etc. However, there are many people who do not experience any symptoms at all.