Key Points about Mononucleosis

  • Mononucleosis, or mono, is a common infection caused by the Epstein-Barr virus.
  • The virus can spread from person to person through saliva.
  • Common symptoms of mononucleosis include swelling in the lymph nodes, tonsils and spleen, as well as a sore throat, fever, and fatigue.
  • Mono is commonly treated at home by managing symptoms through rest, hydration, and a nutritious diet.
  • Symptoms may last from a few weeks to up to a few months.

Overview

Over 90 percent of adults in the United States have been infected with the Epstein-Barr virus—the virus responsible for mononucleosis. Also known as mono, this condition can cause swelling in the lymph nodes, tonsils and spleen, as well as symptoms such as a sore throat, fever, and fatigue. While mono can infect—and affect—anyone, teenagers and young adults may be more likely to experience severe symptoms.

There is no medical treatment for mono. It is commonly treated at home by managing symptoms through rest, hydration, and a nutritious diet.

Call your doctor if you have symptoms of mononucleosis that persist past one to two weeks. 

Mononucleosis causes 

Mono is caused by the Epstein-Barr virus, which is transmitted from person to person via saliva. Saliva carrying the virus can spread from an infected person through shared food or drinks, shared eating utensils, kissing, coughing or sneezing.

Mononucleosis risk factors

Most adults in the United States have been infected with the virus that causes mono. Not all people, however, experience symptoms upon infection.

People who are infected for the first time as teenagers or young adults may be more likely to experience symptoms. Although the virus remains in the body forever, most people do not experience symptoms again after the initial infection. 

Mononucleosis symptoms

While people of any age can be infected with the Epstein-Barr virus, symptoms of mono are often most severe in teenagers and young adults. In some people—particularly in young children—symptoms are mild and improve within several weeks. In others, symptoms pay persist for up to six months.

Common symptoms of mono include:

  • Intense fatigue
  • A sore throat
  • Fever
  • Body or muscle aches
  • Headaches
  • Swollen tonsils, lymph nodes, or spleen
  • Rash on the skin

Certain symptoms may last for only a few days to a few weeks, while others may persist for the duration of the illness.

Mononucleosis complications

Complications from mono are rare but can be serious. Possible complications include:

  • An enlarged spleen, which may rupture
  • Liver problems, such as hepatitis or jaundice
  • Anemia
  • Swollen tonsils that may impact breathing

People with compromised immune systems are more likely to develop complications from mono.

Mononucleosis diagnosis

When diagnosing mono, your doctor will review your symptoms and conduct a physical examination. Your doctor may also perform tests such as:

  • An antibody test, to search for antibodies in the blood that are fighting the virus
  • A test of white blood cell count, to assess whether your body may be fighting an infection

Mononucleosis treatment

Because there is no medical treatment for mononucleosis, the condition requires using home remedies to alleviate symptoms. At-home treatment for mononucleosis includes:

  • Resting often
  • Staying hydrated
  • Maintaining a nutritious, balanced diet
  • Taking over-the-counter pain relievers, as needed

When to seek care

Call your doctor if you have symptoms of mononucleosis that do not improve within one to two weeks.

Next Steps

While it is hard to know how and when to avoid acquiring mononucleosis, you can prevent its transmission to others by refraining from kissing, and from sharing items such as eating utensils until your symptoms have gone away.