Infectious Mononucleosis - Topic Overview

Topic Overview

What is mononucleosis?

Mononucleosis, also called “mono,” is a common viral illness that can leave you feeling tired and weak for weeks or months. Mono goes away on its own, but lots of rest and good self-care can help you feel better.

What causes mono?

Mono is caused by the Epstein-Barr virus (EBV). It is most often seen in adolescents and young adults. Children can get the virus, but it often goes unnoticed because their symptoms are mild. Adults usually do not get mono, because they have immunity to the virus.

Mono can be spread through contact with saliva, mucus from the nose and throat, and sometimes tears. Because the virus can be spread through kissing, it has earned the nickname the “kissing disease.” If you have mono, you can avoid passing the virus to others by not kissing anyone and by not sharing things like glasses, eating utensils, or toothbrushes.

As soon as you get over mono, your symptoms will go away for good, but you will always carry the virus that caused it. The virus may become active from time to time without causing any symptoms. When the virus is active, it can be spread to others.

What are the symptoms?

The most common symptoms of mono are a high fever, a severe sore throat, swollen glands and tonsils, and weakness and fatigue. Symptoms usually start 4 to 6 weeks after you are exposed to the virus.

Mono can cause the spleen to swell. Severe pain in the upper left part of your belly may mean that your spleen has burst. This is an emergency.

How is mono diagnosed?

Your doctor will ask you questions about your symptoms and examine you. You may also need blood tests to check for signs of mono (monospot test) and the Epstein-Barr virus. Blood tests can also help rule out other causes of your symptoms.

How is it treated?

Usually only self-care is needed for mono.

• Get plenty of rest. You may need bed rest, which could keep you away from school or work for a little while.
• Gargle with salt water or use throat lozenges to soothe your sore throat.
• Take acetaminophen (such as Tylenol) or ibuprofen (such as Advil) to reduce fever and relieve a sore throat and headaches.
• Avoid contact sports and heavy lifting. Your spleen may be enlarged, and impact or straining could cause it to burst.

In severe cases, medicines called corticosteroids may be used to reduce swelling of the throat, tonsils, or spleen.

Frequently Asked Questions