Mono: 5 Things You May Not Know About the ‘Kissing Disease’

September 28, 2026

Mononucleosis, or mono, is a common viral infection that most often affects teens and young adults. You may know mono as the “kissing disease,” named for one of the ways it can spread.

Despite how common mono is, there are many misconceptions about the illness. University Hospitals Rainbow Babies & Children’s pediatrician Christopher Meyer, MD, shares five facts you might not know about mono.

1. Up to 95% of people have been exposed to the virus that causes mono by time they reach adulthood.

The Epstein-Barr virus, a type of herpes virus, causes most cases of mono. Because the virus is so common, most people are exposed to it during childhood or adolescence. Young children who are exposed often don’t experience symptoms, or their symptoms are so mild they are not diagnosed.

Teens and young adults aged 15-24 have the highest risk of developing full-blown mono symptoms, says Dr. Meyer. It’s estimated that about one in four young adults exposed to the virus will develop classic mono symptoms such as fever, fatigue, sore throat, swollen lymph nodes and muscle aches. Close contact in high schools and on college campuses also contribute to the spread among this age group.

2. Mono is not as contagious as other common viruses, but you can continue to spread it even after you’ve recovered.

Mono is considered a moderately contagious illness and is primarily spread through saliva. It is less transmissible than other viruses such as colds, flu and COVID-19 because it requires larger droplets to spread and usually involves direct contact with an infected person, explains Dr. Meyer. Nicknamed the kissing disease because of this mode of transmission, it also can spread through sharing eating utensils, drinks, water bottles or lip balm.

Mono is most contagious during the two to four weeks you have symptoms, but you may continue to shed the virus for weeks or even months after you start feeling better. This means you can potentially spread mono even after your symptoms have gone away.

Mono also has a longer incubation period than many other viruses. It can take 4-8 weeks after exposure to the virus to develop any symptoms.

3. There is no cure for mono, but at-home treatment can help ease symptoms.

Treatment for mono is usually focused on relieving symptoms with rest, hydration and nutrition. Over-the-counter medications such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen can help manage fever, muscle aches, sore throat and other discomfort. Gargling with salt water and over-the-counter lozenges or sprays can help relieve a sore throat as well.

4. It’s important to restrict sports and activities if you have mono.

Reducing your activity level during a mono infection and recovery is important to lower the risk of spleen injury. Mono can often cause an enlarged or swollen spleen, making it more fragile and prone to tears or rupture. Dr. Meyer says patients are typically advised to avoid athletic activity for approximately three weeks, followed by a gradual return to activity as advised by their healthcare provider. Most patients recover in 2-4 weeks and return to a normal activity level within 2-3 months.

5. The mono virus remains in the body after recovery, but most people are immune to re-infection.

After you recover from mono, the virus remains in your body in an inactive state. For most people, this does not cause ongoing symptoms or health problems. Your immune system develops lasting protection after the initial infection, making it uncommon to develop mono again. While the virus can occasionally become active again, especially in people with compromised immune systems, most healthy people do not experience symptoms or become sick from it.

Ways to Prevent Mono and Reduce the Spread

There is no vaccine for mono. While there is no foolproof way to prevent it, you can take simple steps to lower your risk and help prevent spreading mono to others. Because mono is spread through saliva, avoid sharing cups, water bottles, food, utensils, toothbrushes, lip balms or other items that come into contact with your mouth. It’s also best to avoid kissing someone who has mono while they are recovering.

If you have mono, practicing good hand hygiene and covering coughs and sneezes can also help reduce the spread of germs. Since the virus can remain in saliva for months after symptoms improve, continue taking precautions even after you feel better.