Mononucleosis (Mono)

Mononucleosis, commonly known as mono or glandular fever, is a viral infection that usually affects teenagers and young adults, especially college students. But anyone can get it. 

With it, you may have symptoms like extreme fatigue, weakness, sore throat, swollen lymph nodes and fever. Symptoms can last weeks or months.

Mono isn’t usually life-threatening, but it can make you very uncomfortable and disrupt your life. Complications can include an enlarged spleen and liver problems. People with severe cases of mono or people with weakened immune systems are at higher risk for complications.

Causes of mononucleosis

The Epstein-Barr virus (EBV), a common virus in the herpes family, usually causes mono (but other viruses or infections may sometimes cause it). EBV multiplies in the throat and nose and mainly spreads through saliva and close contact. That’s why mono is nicknamed the “kissing disease.”

Almost everyone gets infected with EBV in childhood or early adulthood. If you get infected with EBV you may have mild, flu-like symptoms or no signs or symptoms at all. That’s usually the case if infants or young children get infected.

But in some cases, especially if your body first comes into contact with EBV as a teenager or young adult or you have a weakened immune system, you may get mono. That’s because the virus makes a type of white blood cell (lymphocyte) enlarge and reproduce, triggering symptoms.

After you’re infected with EBV it stays dormant in your body for the rest of your life. It may sometimes reactivate without causing symptoms. That means that after infection, you could be contagious from time to time even if you don’t have symptoms.

Symptoms of mononucleosis

Mono’s symptoms usually show up a month or two after you’re infected. They may be mistaken for strep throat or the flu. They can limit what you can do for several weeks and include:

• Fatigue that’s constant
• Sore throat and swollen tonsils that may have white spots
• Swollen lymph nodes in the groin, neck and armpits
• Fever, sometimes with chills
• Sore or stiff muscles
• Loss of appetite
• Abdominal pain from an enlarged spleen
• Feeling weak or unwell

Less-common symptoms include:

• Chest pain
• Cough
• Shortness of breath
• Headache
• Stiff neck
• Nosebleed
• Skin rash or hives
• Mild liver damage that can cause temporary jaundice
• Fast heart rate
• Light sensitivity

Fatigue and sore throat are usually worse for the first two to four weeks. Some people fully recover in a few weeks while it can take others a few months. 

How mononucleosis spreads

Mono is often transmitted in schools, colleges and social gatherings. It spreads through:

• Saliva
• Sharing drinks or silverware
• Toys that children have drooled on
• Droplets from coughing or sneezing
• Blood and semen
• Less commonly, blood transfusions or organ transplantation

If you’re infected, you can reduce the risk of spread by not kissing others, washing your hands regularly and keeping things like drinks, utensils, lip balm and toothbrushes to yourself.

Complications of mononucleosis

Mono can lead to several complications such as:

• Enlarged spleen (splenic involvement or splenomegaly): This enlargement can increase the risk of a ruptured spleen, although this is rare.
• Liver problems: In some cases, mono can cause liver inflammation (hepatitis), with symptoms like jaundice (yellowing of the skin and eyes), abdominal pain and abnormal liver function.
• Anemia: Low levels of red blood cells and hemoglobin.
• Thrombocytopenia: Low platelet counts.
• Myocarditis: Inflammation of the heart muscle.
• Nervous system complications: Meningitis, encephalitis or Guillain-Barré syndrome. These are rare.
• Swollen tonsils: They can block breathing.

You are at higher risk of developing complications if you have a weakened immune system due to HIV/AIDS, organ transplant, immunosuppressive medications, cancer treatment or other causes.

Conditions mistaken for mononucleosis

Mononucleosis (mono) shares symptoms with several other common illnesses, including:

• Strep throat: Both strep throat and mono can cause a severe sore throat, fever and swollen lymph nodes. But strep throat is caused by a bacterial infection (group A Streptococcus), not EBV.
• Influenza (flu): The flu shares symptoms like fever, fatigue and body aches with mono. But the flu is caused by different types of influenza viruses and usually has more respiratory symptoms than mono.

Diagnosing mononucleosis

If you think you might have mono or have symptoms that last more than 10 days, see a health care provider. To diagnose it, they may perform these evaluations and tests:

• Physical exam to check for symptoms like fever, sore throat, swollen lymph nodes and an enlarged spleen.
• Blood test for antibodies the immune system produces in response to the Epstein-Barr virus and for high levels of white blood cells that show you have an infection.

It’s important to get an accurate diagnosis so you can avoid unnecessary treatment, treat symptoms and take steps to prevent transmission and complications.

Contact a provider right away if you have:

• Abdominal pain
• Trouble breathing
• Fever over 101.5°F that doesn’t get better
• Severe headache
• Severe sore throat or swollen tonsils
• Weak arms or legs
• Yellow eyes or skin

Call 911 or go to an emergency room if you have:

• Sharp, severe abdominal pain that comes on suddenly
• A stiff neck
• Severe weakness
• Trouble swallowing or breathing

Treating mononucleosis

There’s no vaccine to protect against mono and no cure for mono. It can take a while to recover and return to your normal activities. Treating it focuses on relieving symptoms and helping your body heal with:

• Rest, reducing physical activity and getting lots of sleep.
• Drinking plenty of fluids, such as water and electrolyte-rich drinks, to help you stay hydrated. Avoid alcohol, which can worsen the effects mono has on your liver.
• Throat lozenges to help your sore throat feel better.
• Over-the-counter (OTC) pain relievers, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin), to help reduce fever and discomfort. Avoid aspirin, since it’s linked with the risk of Reye's syndrome in viral illnesses. Reye’s syndrome can cause liver failure and death.

In some cases, you may need corticosteroids to reduce swelling in the throat and tonsils or other treatments for severe symptoms.

Antiviral medications and antibiotics don’t help with mono, but you may need antibiotics if you have another infection at the same time. Don’t take penicillin or related antibiotics like ampicillin or amoxicillin if you have mono, since they can cause a rash.

If you have mono, you should avoid contact sports, strenuous exercise, heavy lifting and other activities that could cause trauma to your abdomen for at least a month after your symptoms clear up. That’s because when you have an enlarged spleen, which is a common complication of mono, it’s more likely to rupture. A ruptured spleen is a serious issue that could need emergency surgery.

You’ll probably start feeling better in a few weeks, though you may feel tired for a few months. Take it slow, don’t overdo it and listen to your body. Choosing a healthy diet, getting enough rest and avoiding alcohol and strenuous activities can help you recover more quickly.

Getting care

With mono, you’re likely to recover with rest and self-care. Talk to a health care provider if symptoms get worse or if:

• You have new symptoms, such as severe abdominal pain, difficulty breathing or yellow skin and eyes (jaundice).
• Signs of complications such as severe throat swelling, persistent fever or fatigue that doesn't improve after several weeks.

If you need care for mono, reach out to the experts at Banner Health. Our team of providers can evaluate your symptoms and help ensure you get the treatment you need so you can recover and get back to your regular activities as quickly as possible.