The Three Stages of Mononucleosis

Mononucleosis, or mono for short, is not simply a viral infection with the Epstein-Barr virus (EBV). It means someone is infected with EBV or another virus and actually has symptoms. So the virus is common but the disease is not, since more people are asymptomatic. Almost all mono infections are caused by EBV, but 10% of cases are caused by other viruses such as an adenovirus, which causes cold- or flu-like illnesses, and cytomegalovirus, which can lead to hepatitis.

Over the course of a mono infection, a person will experience three different stages of the disease. In each stage, the infection will present with different symptoms and health complications.

sick teenager lying in bed

chee gin tan / Getty Images

Stage 1: Prodrome

The prodrome stage of mono is the earliest stage in which symptoms begin to appear. The length of time it takes to start showing symptoms after contracting mono, known as the incubation period, is roughly four to six weeks. This can make it difficult to determine when the initial infection occurred. During the prodrome stage, symptoms begin to develop. They could include fatigue and malaise. These symptoms last three to five days on average.

In most cases, symptoms do not appear at all. Those who are asymptomatic are typically children under the age of 10. In those who do show symptoms, the symptoms are the first sign of a mono infection, and the infection will advance to the next stage.

Stage 2: Acute Phase

Following the prodrome stage is the acute phase. Symptoms become more pronounced. They consist of fever, inflammation or swelling in the lymph nodes, and sore throat. Severe fatigue is also present at this phase. Other symptoms that could be present in those with a mono infection include:

  • Headaches and body aches
  • Swelling of the liver, spleen, or both
  • Rash

In more severe cases, the liver can become damaged. This can lead to other more serious symptoms such as jaundice. In extremely rare cases, mono can lead to liver failure. Since the spleen can also become affected by mono, some people may experience abdominal pain. Spleen rupture has been reported.

Other potential complications include:

  • Infection in the throat that leads to an accumulation of pus behind the tonsils (peritonsillar abscess)
  • Inflammation of the heart (myocarditis)
  • Upper airway obstruction
  • Inflammation of the brain (encephalitis)
  • Water in the lungs (pleural effusion)

Not everyone will experience all of the symptoms. The symptoms could also appear at different times throughout the course of the infection.


Currently, there is no medication or vaccine that can prevent or cure mono. Typically, the illness will need to be fought off by the immune system. Therefore, it's important for someone who has mono to rest and get plenty of fluids to help with their recovery.

Depending on the severity of the infection, over-the-counter or prescription medications may be used to help a person cope with symptoms such as pain and fever while their body fights off the virus. Medications that help to lower inflammation can also help cope. Pain relievers such as Advil (ibuprofen) should be used sparingly because of the increased risk of liver complications.

In more severe cases where there are complications that involve the liver or other organs, other courses of treatment will be necessary to help reduce the virus’ impact on the organ systems. In the case of some of the more serious complications, doctors may prescribe corticosteroids.

How to Avoid Mono

The best way to avoid getting mono is to avoid kissing or sharing drinks, food, or personal items with people who have the virus. Practicing good hygiene can also help prevent catching mono.

Stage 3: Convalescent Phase

The convalescent phase occurs when a person starts to recover from the disease. Typically, most of the symptoms have subsided by this stage. However, fatigue and weakness can still linger. This stage can last anywhere from three to six months.


During the convalescent phase, people with mono are still tired and weak from their bodies fighting off the infection. They may tire out more quickly after normal daily activities. If someone has an inflamed or enlarged spleen, they should avoid any exercise or physical activities that could lead to spleen rupture.

Mononucleosis Timeline

The timeline from the initial transmission of mono to a full recovery can differ significantly from person to person. In the first four to six weeks after a person catches the virus, they may not know they have it because of the long incubation period. When symptoms begin to appear in the prodrome phase, they last roughly three to five days before progressing to full-blown mono symptoms. The disease itself will typically last anywhere from two to six weeks, with most people being sick for about a month. The recovery period can last up to six months. Taking everything into consideration, from start to finish, a case of mono can last up to 10 months.

Long-Term Effects of Mono

Studies have shown that EBV may be linked to endemic Burkitt’s lymphoma and Hodgkin lymphoma. Mono has also been associated with an increased risk of developing autoimmune diseases like multiple sclerosis (MS).

In rare cases, people with mono may develop a chronic active Epstein-Barr virus (CAEBV) infection, which occurs when EBV doesn't become dormant and cannot be controlled. This disorder can occur in those with a first-time infection or if the virus reactivates within the body after a person has already recovered from the disease.

A Word From Verywell

The virus that can cause mono is extremely common, and chances are you and most of the people you know get it at some point in life. However, mono itself is much less common since most people who are infected with EBV don't ever have symptoms. It can take a long time for someone to recover from mono once they become infected. To avoid the unpleasant symptoms like fatigue, it's important that you practice good personal hygiene and prevent catching it from others who have it. Even if you do come down with mono, the good news is that the majority of people who have the virus recover fully at home with plenty of rest and liquids. You can ease the discomfort of some of your symptoms with over-the-counter medications as well.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Mononucleosis (mono). Updated August 3, 2020.

  2. Becker JA, Smith JA. Return to play after infectious mononucleosis. Sports Health. 2014 May;6(3):232-238. doi:10.1177/1941738114521984

  3. Stock I. Pfeiffer'sches Drüsenfieber. Eine "Kinderkrankheit" von grosser medizinischer Bedeutung [Infectious mononucleosis—a "childhood disease" of great medical concern]. Med Monatsschr Pharm. 2013 Oct;36(10):364-368.

  4. Centers for Disease Control and Prevention. Epstein-Barr Virus and Infectious Mononucleosis. Updated September 28, 2020.

  5. Johns Hopkins Medicine. Infectious Mononucleosis.

  6. Zhang L, Zhou P, Meng Z, Pang C, Gong L, Zhang Q, Jia Q, Song K. Infectious mononucleosis and hepatic function. Exp Ther Med. 2018 Mar;15(3):2901-2909. doi:10.3892/etm.2018.5736

  7. Herold J, Grimaldo F. Epstein-Barr Virus-induced Jaundice. Clin Pract Cases Emerg Med. 2020 Jan 21;4(1):69-71. doi:10.5811/cpcem.2019.10.45049

  8. Dunmire SK, Hogquist KA, Balfour HH. Infectious Mononucleosis. Curr Top Microbiol Immunol. 2015;390(Pt 1):211-240. doi:10.1007/978-3-319-22822-8_9

  9. Kimura H, Cohen JI. Chronic Active Epstein-Barr Virus Disease. Front Immunol. 2017 Dec 22;8:1867. doi:10.3389/fimmu.2017.01867