Expected Course Most children only have mild symptoms for a week. Even in the adolescent or adult where symptoms may be more severe, mononucleosis usually runs its course in three to four weeks. However, in a small number of people, the disease may linger for six months or longer. Don't despair if you do not seem to improve right away. Your vigor will return in a matter of time.
Complications are rare.
The most common complication is dehydration from not drinking enough fluids. Breathing or swallowing may be obstructed by enlarged tonsils, adenoids, and other lymph tissue in the back of the throat. On rare occasions, the enlarged spleen will rupture if the abdomen is hit or strained, causing internal bleeding, shock, and even death. Treatment Unfortunately, there is still no drug that can be used to treat a viral infection like mononucleosis the way that antibiotics are used to treat bacterial infections. However, your doctor may prescribe these drugs if you develop a bacterial infection, like an ear infection or strep throat, on top of the mononucleosis.