Mononucleosis is an infectious illness that’s usually caused by the Epstein-Barr virus (EBV). It’s also called mono or the kissing disease. You can get the virus through kissing as well as things like sharing drinks or silverware.
Many people are exposed to EBV as kids. But that doesn’t always mean you’ll get mono. You can carry the virus in your body for your entire life without ever having symptoms of mono.
EBV is part of the herpes virus family. Most people are exposed to it at some point in their lives. In the U.S., about 85% to 90% of adults carry the virus by the time they’re 40.
Swollen lymph nodes
Loss of appetite
Your doctor can usually diagnose mono based on your symptoms. They might also check for swelling in your tonsils, lymph nodes, and liver or spleen.
They can confirm a mono diagnosis with blood tests including:
Complete blood count (CBC). Your doctor will look at your white blood cells, including whether any of them are unusual or whether you have more than usual.
Antibody tests. Your doctor will look for proteins that your immune system creates in response to EBV.
Swollen tonsils - They might narrow your airway, making it harder to swallow or breathe through your mouth.
Enlarged spleen - If it becomes severe, your spleen can burst. This causes a sudden sharp pain on the left side of your upper belly. If you have pain like this, it’s an emergency. Get medical care right away - You may need surgery.
Liver problems - You might have hepatitis or jaundice.
Blood problems - Your body might destroy too many of your red blood cells (hemolytic anemia). Or your blood might not have enough platelets (thrombocytopenia).
Heart problems - Your heart muscle might become inflamed (myocarditis), or you might have an uneven heartbeat.
Nervous system problems - This can include seizures, brain inflammation (encephalitis), or inflammation of the tissues covering your brain (meningitis).
No medications treat mono. Antibiotics and antivirals don’t work on EBV. Things that may help you feel better include:
Lots of rest
Lots of fluids
Over-the-counter pain relievers, like acetaminophen or nonsteroidal anti-inflammatory drugs, for fever and pain
Corticosteroid medication for swelling in your throat
There’s no vaccine to prevent mononucleosis.
EBV can stay in your saliva for months after you’re infected, so even if you don’t have symptoms or feel sick, you may be able to spread it.
To lower your chances of getting mono, wash your hands often and try not to share things like drinks, silverware, or toothbrushes with other people.