In most cases of mononucleosis, the prognosis is fairly good. Usually, the symptoms of mononucleosis (mono) get better within 1 or 2 months without treatment. The symptoms of mono that tend to continue for the longest time are fatigue and body aches. While the mononucleosis prognosis can be worse (such as when complications occur), the illness is rarely fatal. It is also rare for symptoms to last longer than 4 months in people with mononucleosis.
Symptoms of mononucleosis (mono) usually get better in 1 or 2 months without any treatment. The sore throat and fever usually improve within 2 weeks, and the swollen lymph nodes within 3 weeks, although the improvement can vary. The symptoms of mono that usually continue for the longest time are the tiredness and body aches.
Because mono symptoms can vary among individuals, some people with the illness may be able to return to their full activities very quickly. Most people can return to work or school after 3 to 4 weeks. Others may be exhausted and unable to return to their full activities for months.
It is also possible for complications of mono to occur. Although these mono complications occur infrequently, when they do occur, they can be dramatic; however, mononucleosis is rarely fatal.
It is important to note that symptoms related to infectious mononucleosis, caused by Epstein-Barr virus (EBV) infection, seldom last for more than 4 months. When such an illness lasts for more than 6 months, it is frequently called chronic EBV infection; however, valid laboratory evidence for continued active EBV infection is seldom found in these patients. The illness should be further investigated to determine if it meets the criteria for chronic fatigue syndrome (CFS). This process includes ruling out other causes of chronic illness or fatigue.