• Mononucleosis

    (Infectious Mononucleosis; Mono)


    Mononucleosis is a viral disease characterized by fever, sore throat, swollen lymph glands, and fatigue.
    Swollen Glands
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    Mononucleosis is caused by the Epstein-Barr virus (EBV). Found mainly in saliva and mucus, EBV is passed from person to person by intimate behavior, such as kissing.

    Risk Factors

    Many people get EBV during their lifetime. Factors that increase the likelihood that EBV will develop into mononucleosis include:
    • Contracting EBV after age 10
    • Lowered immune resistance, due to other illness, stress, or fatigue
    • Living in close quarters with a large number of people, such as in a college dormitory
    One episode of mononucleosis usually produces permanent immunity.


    Signs of mononucleosis usually begin 4-7 weeks after you were exposed to the virus. The initial symptoms may be a sense of general weakness that lasts about one week. This is followed by symptoms that may include:
    • High fever
    • Severe sore throat
    • Swelling of the lymph nodes
    • Fatigue
    • Loss of appetite
    • Muscle aches
    • Enlargement of the spleen
    • Swollen tonsils
    • Mild jaundice


    Your doctor will ask about your symptoms and medical history. A physical exam will be done. Diagnosis is based on:
    • Your age
    • Four primary symptoms: Two primary tests:
      • Blood tests and mono spot tests
      • Throat culture—to check for strep throat, which can complicate mono


    There is no treatment to cure mononucleosis or to shorten the length of the illness. It usually runs its course in 4-6 weeks, although the fatigue may last longer.
    During the first few weeks after diagnosis, patients should avoid contact sports. Inflammation of the spleen from mononucleosis puts individuals at high risk of splenic rupture. This can require surgery, and in rare cases, can be fatal.
    Treatment includes:

    Relief of Symptoms

    • Taking nonprescription pain relievers to lessen aches and pains and control fever— avoid aspirin, especially in children
    • Gargling with warm, salty water to relieve sore throat
    Steroids are sometimes used if the swelling in the throat is interfering with breathing. They can also be used if a complication involving low platelet counts or anemia occurs. This treatment has not been shown to be helpful in mild cases.


    • Rest and fluids
    • No heavy lifting or exercise for at least several weeks after recovery to decrease the risk of rupturing an enlarged spleen
    If you are diagnosed with mononucleosis, follow your doctor's instructions.
    If you are diagnosed with mononucleosis, follow your doctor's instructions.


    Most people contract the EBV virus sometime during their lives. Prevention is geared toward decreasing the likelihood that EBV will develop into mononucleosis. Follow these guidelines to decrease your risk:
    • Avoid intimate contact, especially kissing, with anyone who has active mononucleosis.
    • Eat a healthful diet.
    • Avoid excess stress.
    • Get enough rest.


    Centers for Disease Control and Prevention http://www.cdc.gov

    National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov


    About Kids Health http://www.aboutkidshealth.ca

    The College of Family Physicians of Canada http://www.cfpc.ca


    Balfour HH Jr, Hokanson KM, et al. A virologic pilot study of valacyclovir in infectious mononucleosis. J Clin Virol. 2007;39:16-21.

    Berkow R. The Merck Manual of Medical Information. 17 ed. New York, NY: Simon and Schuster, Inc; 2000.

    Infectious mononucleosis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 28, 2013. Accessed March 25, 2013.

    Luzuriaga K, Sullivan JL. Infectious mononucleosis. N Engl J Med. 2010 May 27;362(21):1993-2000.

    Mononucleosis. Academy of Family Physicians website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/mononucleosis.html. Updated November 2010. Accessed March 25, 2013.

    Revision Information

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