(Infectious Mononucleosis; Mono)
Mononucleosis is a viral disease characterized by fever, sore throat, swollen lymph glands, and fatigue.
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.
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/swollen tonsils
- Swelling of the lymph nodes
- Loss of appetite
- Muscle aches
- Enlargement of the spleen or liver
- Mild jaundice
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Diagnosis is based on:
- Symptoms, which can differ according to age; young children may be difficult to diagnose
Four primary symptoms:
- Swollen lymph nodes
- Sore throat
Two primary tests:
- Blood tests and mono spot tests
- Throat culture—to check for strep throat, which can resemble mononucleosis and also complicate mononucleosis
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. In rare cases, it can be fatal.
Relief of Symptoms
Symptoms can be eased by:
- Taking nonprescription pain relievers to lessen aches and pains and control fever
- Gargling with warm, salty water to relieve sore throat
Note: Aspirin is not recommended for children or teens with a current or recent viral infection. This is because of the risk of Reye syndrome. Ask your doctor which other medicines are safe for your child.
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.
Follow these comfort measures:
- Get plenty of rest and fluids
- Do not lift anything heavy or exercise for at least several weeks after recovery to decrease the risk of rupturing an enlarged spleen
- Avoid contact or collision sports while you have symptoms or an enlarged spleen
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
National Institute of Allergy and Infectious Diseases
About Kids Health
The College of Family Physicians of Canada
Balfour HH Jr, Hokanson KM, et al. A virologic pilot study of valacyclovir in infectious mononucleosis. J Clin Virol. 2007;39:16-21.
Infectious mononucleosis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 28, 2013. Accessed June 7, 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 June 7, 2013.
Last reviewed June 2013 by Kari Kassir, MD; Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.