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What is mononucleosis?
Mononucleosis (often called “mono”) is a contagious illness. It is usually caused by the Epstein-Barr virus. Some of the symptoms of mono are similar to those of a cold or flu. It is spread through saliva. For this reason, it is sometimes called “kissing disease.” It is most common in teens and young adults. Anyone at any age can get it.
Symptoms of mono
Symptoms often don’t appear until 4 to 6 weeks after you’ve been exposed to the virus. They may not come at the same time, and they may come on gradually. They include:
- sore throat
- swollen glands in your neck and armpits
- swollen spleen or liver
- loss of appetite
Symptoms in young children are generally mild. Symptoms in adolescents and young adults tend to be more severe.
What causes mono?
Most cases of mono are caused by the Epstein-Barr virus. The virus is found in saliva, mucus, and other body fluids. It is often passed from one person to another through kissing. It can be passed through exposure to a cough or sneeze. It also can be passed by sharing food utensils (such as drinking glasses, spoons, and forks) with someone who has mono.
How is mono diagnosed?
Your doctor will probably first ask you some questions about your symptoms. He or she will do a physical exam. They may look for:
- swollen lymph nodes in your neck
- swollen tonsils
- swollen liver or spleen.
They will probably order blood tests to confirm the diagnosis. One common test used to diagnose mono is called the Monospot test. Sometimes other blood tests are needed if the results of the Monospot test aren’t clear.
Can mono be prevented or avoided?
There is no vaccine to prevent mono. The best thing you can do to avoid it is to stay away from anyone you know who has it. Don’t kiss them or share utensils or other personal items.
There isn’t a cure for mono. The virus will go away on its own. Symptoms usually last about 4 weeks. The main goal of treatment is to relieve your symptoms. Here are some steps you can take:
- Rest. Sleep helps your body fight infection.
- Drink plenty of fluids. They help prevent dehydration.
- Soothe a sore throat. Gargle with salt water or suck on throat lozenges, hard candy, or flavored frozen desserts (such as Popsicles).
- Relieve the pain. Take acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) to relieve pain and fever. Do not give aspirin to children. Aspirin has been associated with a rare disease in children called Reye’s syndrome. Reye’s syndrome is a serious illness that can lead to death.
Do I need an antibiotic?
Antibiotics are not effective against mono. Mono is caused by a virus. Antibiotics don’t work against viruses. If you have a bacterial infection (such as strep throat) in addition to having mono, your doctor may give you an antibiotic to treat that infection.
What about sports and exercise?
Avoid sports, physical activities or exercise of any kind until your doctor tells you it’s safe. Moving around too much puts you at risk of rupturing (bursting) your spleen, especially if it is enlarged. You need to avoid physical activities and contact sports for about 3 to 4 weeks after you’ve had mono.
Living with mono
Most people feel better in 2 to 4 weeks. Fatigue may last for several more weeks. In some cases, symptoms can last for 6 months or longer. In addition, mono can sometimes have complications. The main complication is the enlargement of the spleen. The spleen is like a large gland. It’s located in the upper part of your abdomen on the left side. It helps filter your blood. In severe cases of mono, the spleen can rupture (tear open).
A ruptured spleen is rare in people who have mono. But it’s wise to be aware of the signs:
- sharp pain in the left upper part of your abdomen (under the left chest)
- feeling lightheaded
- feeling confused
- blurred vision
Other complications can include anemia, nervous system problems, or hepatitis with jaundice. They could cause symptoms including:
- breathing difficulty
- persistent high fevers (101.5 degrees or higher)
- severe headache
- weakness in arms or legs
- yellow color in you eyes or skin (jaundice)
- trouble swallowing.
Call your doctor right away if you notice any of the above symptoms.
Questions to ask your doctor
- How did I get mononucleosis?
- I have mononucleosis. Should my girlfriend get tested?
- What is the best treatment for me?
- How long will it be before I can exercise safely?
- How long should I keep my child home from school?
- How can I make sure that the rest of my family doesn’t get mono?
- Are there any medicines I can take to feel better?
- How long will I be contagious?
- If I start having pain in my side, should I call my doctor immediately?
- If I have mono once, will I get it again?
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.