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Mononucleosis - Mono

What is Mono?

"Mono" or infectious mononucleosis is characterized by fever, sore throat, and significant lymph node swelling. It is caused by the Epstein-Barr virus (EBV). When tested, approximately 95% of adults have been found to have been exposed to this virus at some time in the past, although many are not aware of having been infected. Some infections are very mild or even asymptomatic.

Mono is not highly contagious through routine contact and is rarely passed from one family member to another. However, because EBV is present in saliva, the disease can be spread by intimate oral contact, hence the term, the “kissing disease.” It can also be spread by sharing food, drinks or utensils.

Mono is an illness that gets better without any particular medical treatment; your body’s immune system usually fights off the infection without serious complications. However, despite the brevity of the acute stage, fatigue and lethargy can last for 2 to 3 months. Antibodies will develop which probably protect you from re-infection.

Signs and Symptoms:

Early signs and symptoms can include:

  • sore throat
  • intermittent fever as high as 103°
  • headache
  • muscle aches and pains
  • swollen lymph glands in the neck, the armpits, and groin.
  • fatigue

The liver and spleen are also involved. Infection in these organs often causes no symptoms but may cause nausea, decreased appetite, and abdominal pain.

The average incubation period ranges from 30 to 45 days. Then early symptoms usually persist for 7 to 10 days. Although most people with mono require more sleep, they do not need to stay in bed continuously. The length of recovery varies among individuals depending on the severity of the disease. Most patients feel normal three weeks after the onset of symptoms. In some, complaints such as fatigue and lack of energy last for weeks or months.


Since the symptoms may not be very specific, accurate diagnosis usually requires a blood test. Positive test results may not occur until a week or more after symptoms have developed. There is a specific blood test for EBV antibodies called the Monospot. In addition to the mono spot test, your provider may order a complete blood count and liver function tests.

Diagnosis is based on your symptoms, on the results of your physical exam, and often on the results of laboratory tests. Once mono is diagnosed, there is no need for follow-up tests in the majority of cases because the mono test will remain positive for at least six weeks, and in some cases even longer. Subsequent testing within this time period is usually unnecessary and costly. Although follow-up testing may be indicated for abnormal liver function or low platelet counts


The most significant involve the liver and spleen, which can be affected by the virus. The spleen may become enlarged up to 60% of the time and is vulnerable to injury. In extreme cases your spleen may rupture, causing sharp, sudden pain in the left, upper side of the abdomen. If this happens seek medical attention immediately, it can be a life-threatening condition. The liver may become inflamed, causing a mono hepatitis.

Treatment and Self-Care Tips:


  • No exercise during the early illness or while you have a fever.
  • Once you are feeling better, you can gradually return to low impact or low-intensity activities (stationary biking, walking) as tolerated. Do not use weights or do any “gut crunching” exercises. If you overexert too early your fatigue could worsen, your spleen could rupture (see above), and your recovery will be slower.
  • You should not participate in any running, contact sports, wrestling/roughhousing, skating/skateboarding or free weight lifting for at least 4 weeks from diagnosis date.
  • If you have an enlarged spleen or liver you should be re-evaluated by a provider before returning to normal activities

Do not use Tylenol (acetaminophen) because of its effect on the liver.

Do not use Aspirin.

Take Ibuprofen (Motrin or Advil) every 6-8 hours for fever and discomfort unless a health care provider advises against these medications.

Do not drink alcohol, especially if your liver is enlarged or you have jaundice (yellow skin or eyes). Avoid alcohol for six weeks because of its effect on the liver.

Increase your daily fluid intake, and eat at least two "good" meals a day.

Practice good hygiene, including regular hand washing. Do not share food or drink and refrain from kissing for three to six weeks.

How is Mono Treated?

Most people recover completely without any medication. Infrequently, in severe cases, a cortisone derivative may be prescribed to reduce the local swelling of the throat, lymph nodes, liver, and spleen. Your clinician may order a throat culture to detect the presence of streptococcal bacteria (strep), since strep throat may co-exist with mono.

An antibiotic may be prescribed to treat secondary bacterial infection. The antibiotic is not a cure for mono; because it is caused by a virus and viruses do not respond to antibiotics.


In an emergency go to Mount Nittany Medical Center or call 911 for an ambulance.

Test Results and Advice Nurse

Send a secure message to advice nurse via the UHS website or call 814- 863-4463. 


Appointments can be made online via the UHS website, by phone 814-863-0774, or in person. If you are unable to keep your appointment, please call or go online to cancel. Otherwise, you will be charged for the visit. 

This content is reviewed periodically and is subject to change as new health information becomes available. This information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. 12/7/18