The most common cause of a ruptured spleen is blunt trauma to the abdomen, such as that experienced in a car crash or a fall from a significant height. Blunt trauma is the type of trauma that does not directly penetrate the skin, like a stabbing or gunshot wound. Penetrating trauma is less common, but can also lead to a ruptured spleen.
In rare cases, a ruptured spleen can occur spontaneously without trauma. The spleen can become inflamed and enlarged from infection, cancer, or other diseases. The disease that is often associated with a non-traumatic ruptured spleen is mononucleosis, even though the incidence of a ruptured spleen occurs in an estimated .06 to .5 percent of all cases of mononucleosis.
Malaria is another infectious disease associated with a ruptured spleen. Other than the lack of a trauma history, the symptoms of a spontaneously ruptured spleen are similar to those caused by injury.