Mononucleosis is a viral illness that commonly affects teenagers and young adults. Commonly called mono, it's caused by a virus known as the Epstein-Barr virus. By age 35 to 40, 95 percent of American adults have been exposed to the virus. In early childhood, it presents like a mild cold, but it causes mononucleosis if the first exposure occurs in the teen or early adult years.
Mono spreads from person to person via saliva. Common modes of transmission include kissing, sneezing, coughing or sharing straws or utensils. Once people are infected with EBV, they will carry it for the rest of their lives but probably never get symptoms again. Also, in rare instances mono can be caused by other viruses.
Symptoms of Mononucleosis
When a teen or young adult gets mono, the illness typically lasts two to four weeks and goes away on its own. Symptoms include weakness and fatigue, fever, swollen lymph nodes, a sore throat and sometimes sore muscles, headaches, skin rash, swollen tonsils and pain. In very rare instances, mono might lead to heart or central nervous system problems. But most often, the disease is a natural part of life that passes on its own.
Mono is a viral illness, so it cannot be treated with antibiotics. Doctors usually recommend getting plenty of rest and drinking lots of fluids. People with mono can also take over-the-counter pain relievers to help with the symptoms, though aspirin should be avoided because of the risks it presents to the liver. Also, teens and young adults who have been diagnosed with mono are generally advised to not participate in sports for a month after symptoms have subsided. Mono enlarges the spleen, so vigorous activity or contact sports can pose a risk to the spleen.
SOURCES: U.S. Centers for Disease Control and Prevention; KidsHealth, Nemours Foundation