What Is Mono, and How Do You Get It From Kissing? Symptoms, Causes, and Pictures
Key takeaways:
Mononucleosis (mono) is a viral illness. It’s most commonly caused by the Epstein-Barr virus.
Mono is transmitted through any exchange of saliva — not just from kissing. In rare cases, it can also spread through other body fluids like blood or semen.
The best way to prevent the spread of mono is to avoid situations where you exchange saliva with others, like kissing on the mouth or sharing drinks.
Table of contents
Perhaps you’ve heard about the “kissing disease.” It’s commonly known as “mono,” which is short for mononucleosis. This illness is usually caused by the Epstein-Barr virus (EBV), and it can make you feel crummy for a month or so.
Almost everyone — 90% of adults by age 30 — will be exposed to EBV at some point in their life, though not everyone will get mono. While it’s often linked to kissing, mono can be transmitted in other ways, too. No matter how you catch it, there are steps you can take to avoid spreading the virus to others.
What is mono (the kissing disease)?
Mono is a contagious viral illness. Other examples of common viral illness are the common cold, the flu, and COVID-19.
If you catch a virus that causes mono — like after kissing someone else who has it — it infects cells in your mouth, throat, and tonsils. Then it spreads through the rest of your body, and your immune system kicks into gear to fight it off. This immune system response is what makes you feel sick.
What virus causes mono?
Mononucleosis can actually be caused by different viruses. It’s most commonly caused by the Epstein-Barr virus (EBV). Other viruses that can cause mono include:
Cytomegalovirus (CMV)
HIV
Adenovirus
Rubella
Hepatitis
Toxoplasmosis
What’s making your throat hurt? Here are some top causes of a sore throat, including viral infections like mono.
Does mono ever really go away? Learn more about how long mono lasts.
Can you get an STI from kissing? Some sexually transmitted infections (STIs or STDs) can spread through kissing, like herpes simplex virus 1 (HSV-1) and human papillomavirus (HPV). Here’s what you need to know.
Mononucleosis symptoms
It usually takes 4 to 6 weeks after coming in contact with EBV to develop symptoms of mono. Classic symptoms of mono include:
Extreme tiredness
Fever
Sore throat
Swollen lymph nodes in the armpits and neck
Headaches and body aches
Swollen liver or spleen
Rash
Most people have symptoms for about 2 to 4 weeks. But extreme tiredness can last longer, and even stick around for months. On the other hand, some people with mono have no symptoms at all.
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Pictures of mono rash
Mono can cause a rash, though it’s not as common as other symptoms. Mono rash can appear as bumps or discolored areas on your skin (a maculopapular rash). Sometimes, this rash can be itchy. Mono can also cause tiny red-brown spots of bleeding under your skin or in your mouth (called petechiae).
Here are some pictures of the mono rash in different skin tones.
How is mono spread?
Mono viruses are usually spread in saliva. But saliva isn’t the only way it spreads. You can also get mono from other body fluids, like blood and semen.
Here are some of the ways mono can spread:
Kissing
Sharing food or drinks
Sharing eating and drinking utensils
Sharing lipstick or lip gloss
Wet sneezes or coughs
Receiving a blood transfusion (less common)
Receiving an organ transplant (less common)
Having unprotected sex (less common)
How do you get mono without kissing anyone?
Kissing is a common way mono is transmitted. But since the virus stays in saliva, sharing food, drinks, or makeup can spread the virus, too. And as we just saw above, mono can also spread through medical procedures or sexual activity — though these situations aren’t as common.
Can adults get mono?
Yes. But in reality, most cases of mono occur before age 30. It’s especially common in teenagers and young adults between the ages of 15 and 25.
If you’re outside of these age ranges and have symptoms of mono, it’s best to get checked out by your primary care provider since you may have something else going on.
How is mononucleosis diagnosed?
Most of the time a healthcare professional can diagnose mono just based on your symptoms and a physical exam. But in certain cases, they might also order blood tests to confirm that you have mono. These tests include:
White blood cell count: With mono infections, your lymphocyte count (a type of white blood cell) can be high.
Antibody and antigen tests: These tests can determine whether you’ve been infected with EBV or other viruses, either now or in the past.
Monospot test: This used to be a common in-office test because it gave quick results. But it’s not used much anymore because it isn’t very accurate, especially when it comes to detecting EBV.
If your tests don’t show that you have EBV, then your primary care provider might order tests for other viruses that cause mono, like CMV. They may also test you for other conditions that cause similar symptoms to mono — like strep throat, a bacterial infection of the throat.
What is the treatment for mono?
Mono is usually treated with rest and self-care, similar to other viral infections. This means:
Drinking fluids to stay hydrated
Getting plenty of sleep and rest
Using over-the-counter (OTC) medications for fever, aches, and pains (like Tylenol or Advil)
Soothing your sore throat with home remedies, like saltwater gargling or drinking hot tea
If your spleen is enlarged you may also need to avoid contact sports, so check with your primary care provider before starting to do physical activities.
And finally: Skip the antibiotics and antiviral medications. They don’t work for mono. Certain antibiotics can also give you a rash.
How can you prevent spreading mono?
The best way to prevent spreading mono is to avoid sharing body fluids of any kind, especially if you know you’re sick.
If you suspect you’ve been exposed to mono, or you’ve just recovered from an infection in the last few months, you should be especially careful. This includes:
Avoiding sharing your drinks, food, and utensils with other people
Avoiding kissing on the mouth
Using a protective barrier during sex, such as a condom or dental dam
How long are you contagious with mono?
It’s hard to say. You can pass mono any time after you have the infection, even if you don’t have symptoms. This is because EBV, the virus that usually causes mono, stays quietly in your body for life — just like the virus that causes chickenpox.
If you have active symptoms, it’s safe to assume you’re contagious. But even once you feel better, EBV and other viruses can linger in your saliva for months. This means you can be contagious long after your symptoms have gone away.
Dormant EBV can also reactivate in your body later in life. This means that once you’ve had EBV, you can technically become contagious again at any time — even if you don’t have any symptoms.
Frequently asked questions
Probably not. Though EBV stays in your body for life, the virus usually stays dormant. This means that most people who have mono won’t get it again — especially if they’re otherwise healthy. It may be more likely to reoccur in people who are immunocompromised.
Not exactly. You can only get mono from a virus — usually EBV. But there’s some evidence that stress might reactivate the dormant virus in your body. More research is needed before we can say for sure.
Yes and no. For most people, active mono symptoms will go away within 2 to 4 weeks. But after your symptoms are gone, EBV lives in your body for the rest of your life.
The bottom line
Mono is often called the “kissing disease” because it spreads easily through saliva. But it can spread through other body fluids, too, like blood or semen. You can avoid passing mono by not sharing food and drinks, not kissing other people when you’re sick, and using protection when you have sex.
Most people who have mono will feel better within a few weeks. But remember: You can still be contagious even after you’ve recovered. And in some cases, EBV can reactivate in your body years later and make you contagious again — even if you don’t have any symptoms.
Why trust our experts?
Images used with permission from VisualDx (www.visualdx.com).
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