Carl R. Darnall Army Medical Center - Health Library

Mononucleosis

(Infectious Mononucleosis; Mono)

Definition

Mononucleosis (mono) is an infection caused by a virus. It is marked by fever, lack of energy, and swollen glands.

Swollen Glands
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Causes ^

Mono is caused by the Epstein-Barr virus (EBV). Found mainly in saliva and mucus, it is passed from person to person by intimate behavior, such as kissing.

Risk Factors ^

Many people get EBV during their lifetime. Here are factors that raise the chance that EBV will turn into mono:

  • Getting EBV after age 10
  • Lowered immune system due to other illness, stress, or lack of energy
  • Living in close quarters with many people, such as in a college dormitory

Getting mono once means you will be immune to it in the future.

Symptoms ^

Signs of mono start 4 to 7 weeks after you were exposed to the virus. The first symptoms may be a sense of weakness that lasts about 1 week. Next, you may have:

  • High fever
  • Severe sore throat/swollen tonsils
  • Swollen glands
  • Lack of energy
  • Loss of hunger
  • Muscle aches
  • Belly swelling
  • Yellowing of the skin and whites of the eyes— jaundice

Diagnosis ^

You will be asked about your symptoms and health history. A physical exam will be done.

Your bodily fluids may be tested. This can be done with blood tests.

Treatment ^

There is no way to cure mono or to shorten the length of the illness. It lasts 4-6 weeks, but the lack of energy may last longer.

During the first few weeks, you should not play contact sports or lift anything heavy. A swollen spleen puts you at high risk of splenic rupture. This needs surgery. In rare cases, it can be fatal.

Get plenty of rest. Other steps may be to:

  • Take pain relievers, such as ibuprofen
  • Gargle with warm, salty water
  • Drink plenty of fluids
  • Take steroids to reduce swelling in the throat, if advised by your doctor

Prevention ^

You can prevent mono by:

  • Avoiding intimate contact, especially kissing, with anyone who has active mono
  • Do not share drinks or food with anyone who has mono
RESOURCES:

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

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

CANADIAN RESOURCES:

About Kids Health—The Hospital for Sick Children
http://www.aboutkidshealth.ca

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

REFERENCES:

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

Ebell MH, Call M, et al. Does this patient have infectious mononucleosis?: The rational clinical examination systematic review. JAMA. 2016 Apr 12;315(14):1502-1509.

Epstein-Barr virus infection. EBSCO DynaMed Plus website. Available at:https://www.dynamed.com/topics/dmp~AN~T904534/Epstein-Barr-virus-EBV-infection. Updated January 5, 2018. Accessed July 17, 2018.

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

Mononucleosis. Academy of Family Physicians Family Doctor website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/mononucleosis.html. Updated October 24, 2017. Accessed July 17, 2018.

Last reviewed June 2018 by James Cornell, MD  Last Updated: 7/18/18