Spleen diseases can include a variety of conditions, some of which are very serious. Some of the most common spleen diseases include splenic cysts, splenic abscesses, splenic infarction, and splenic tumors. Splenic cysts are small pockets of fluid that develop within the spleen and are often found incidentally during imaging tests. Splenic abscesses are bacterial infections that can cause fever, abdominal pain, and an enlarged spleen. Splenic infarction is usually caused by a blocked artery and can cause severe pain, nausea, and chills. Splenic tumors can be either benign or malignant and can cause abdominal pain, weight loss, and an enlarged spleen. Fortunately, with early diagnosis and treatment, most spleen diseases can be managed successfully.