Enlarged spleens are categorized into three degrees, first, second and third. First degree is the mildest symptom, second degree is moderate, and third degree is severe, also known as megasplenism.
An enlarged spleen is a pathologic feature, and normally, the spleen cannot be felt.
Splenomegaly exceeds the left costal arch, i.e., reaches below the left costal margin. However, the enlargement does not exceed 20mm of the rib margin, i.e., one degree; the enlargement exceeds 20mm of the rib margin, and has not yet reached the navel for the second degree; the lower edge of the enlarged spleen exceeds the navel, or the right edge exceeds the anterior median line, i.e., for the third degree, which is also called megasplenism.
Symptoms of enlarged spleen may be caused by acute infections, acute leukemia, systemic lupus erythematosus, or cirrhosis of the liver. Mild and moderate enlargement can usually return to normal after treatment through infection control. However, severe enlargement, due to the long duration of the disease and the hard texture of the spleen, usually cannot return to normal even after surgery.