Infectious mononucleosis is not a serious disease. 1. Infectious mononucleosis is a reactive proliferative disease of the monocyte macrophage system caused by acute primary EBV infection. The symptoms are varied and the onset of the disease is not the same. The most common symptoms are sore throat and fatigue, and fever, pharyngitis and lymph node enlargement may also occur. 2. Mild cases of infectious mononucleosis usually recover in about 1 month, and more severe cases will disappear completely in 2 to 3 months. The prognosis is generally good, so it is not considered a serious disease. Infectious mononucleosis should be timely to the regular hospital, by the doctor according to the specific condition to give symptomatic treatment in order to recover as soon as possible.