The common clinical causes of slightly thick spleen include infectious lesions, hematologic diseases, and liver cirrhosis caused by various reasons. 1. Infectious lesions: such as sepsis, typhoid fever, etc., can cause increased destruction of red blood cells in the blood circulation, thus causing congestion and thickening of the spleen. 2. Blood system diseases: such as hemolytic anemia, leukemia, etc., which can cause hypersplenism and lead to thickening of the spleen. 3. Liver cirrhosis caused by various reasons: such as alcoholic cirrhosis, viral hepatitis cirrhosis, schistosomal cirrhosis, which can cause portal hypertension, resulting in congestion, enlargement and thickening of the spleen. If thickening of the spleen occurs, it is necessary to go to the hospital as soon as possible to make a clear diagnosis and intervene in time to avoid delaying the condition.