Risk Factors
The EBV virus, which causes mono, is most often spread through saliva. Many people contract the virus during childhood and never notice any symptoms. Once the virus enters the body, it stays there forever, and it can occasionally reactivate at a later time. The reactivated virus can spread to others through saliva, so a person can catch mononucleosis from someone who has no signs of illness. [7]
Complications
Complications of mononucleosis can occasionally be serious.
Enlargement of the spleen:
Mononucleosis may cause enlargement of the spleen. In extreme cases, your spleen may rupture, causing sharp, sudden pain in the left side of your upper abdomen. If such pain occurs, seek medical attention immediately — you may need surgery.
Liver issues
Problems with your liver also may occur:
- Hepatitis. You may experience mild liver inflammation (hepatitis).
- Jaundice. Yellowing of your skin and the whites of your eyes (jaundice) also occurs occasionally.
Less common complications
Mononucleosis can also result in the following less common complications:
- Anemia — a decrease in red blood cells and hemoglobin, an iron-rich protein in red blood cells
- Thrombocytopenia — a low count of platelets, which are blood cells involved in clotting
- Heart problems — an inflammation of the heart muscle (myocarditis)
Complications involve the nervous system — meningitis, encephalitis and Guillain-Barre syndrome. Swollen tonsils — which can block breathing. [8]