Mononucleosis, or mono, can lead to a range of symptoms, including severe fatigue, fever, and a sore throat. However, symptoms typically generally resolve within around 2–4 weeks.

Mono is a common disease in young adults and teenagers. It most commonly develops with exposure to the Epstein-Barr virus (EBV).

Although there are no medical treatments for mono, a person can take steps to manage pain and relieve other symptoms.

Read on to learn more about the symptoms of mono. This article also looks at how long symptoms can last, how to reduce symptoms, and more.

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Symptoms of mono can include:

These symptoms may not develop at the same time. Some people may experience severe symptoms, while others may have milder symptoms.


Mono can cause extreme fatigue, which can continue for a number of weeks and can affect a person’s quality of life long after some other symptoms have resolved.

A 2019 study of 65 people found that participants had some of the criteria of chronic fatigue syndrome in 40% of cases 6 months after the initial infection.

More studies are necessary to assess the long-term effects of fatigue after EBV infection and mono.

Sore throat

People with mono often experience a severe sore throat. It may be worse than other types of sore throat.

Before the sore throat starts, the tonsils may produce discharge. Lesions might also appear on the roof of the mouth, although this is uncommon.


Mono often causes a fever. This can reach as high as 104ºF (40ºC).

The 2019 study mentioned above suggested that a fever this high may last for 2 weeks in people with severe mono, but temperatures of 101°F (38.3°C) can persist for up to 5 weeks.

Swollen glands

Some doctors refer to mono as glandular fever, as it typically causes swelling in the lymph nodes, or glands.

A person may experience swollen glands in the neck or armpits.

Organ swelling

Although less common than other symptoms, mono can cause swelling in the spleen and liver. Up to half of all people with mono develop a swollen spleen, or splenomegaly.

Livers or spleens that swell due to mono may remain swollen after other symptoms, such as fatigue, have resolved.

A person with mono needs to avoid sports, as any potential spleen enlargement may result in rupturing.

Other symptoms

Other symptoms that mono may cause include:

Mono symptoms usually develop 4–6 weeks after exposure to EBV.

The time between exposure and symptoms first appearing is known as the incubation period.

Mono symptoms resolve in 2–4 weeks for most people.

Different symptoms may resolve in different time frames:

  • Sore throat: This usually lasts 3–5 days before slowly starting to feel better.
  • Fever: A person’s body temperature may stay high for 10–14 days.
  • Fatigue: This commonly lasts for several weeks but may continue for months after other symptoms get better.
  • Swollen glands: These can last for a few months.

Some symptoms may last for at least 6 months in some people.

Learn more about how long mono lasts.

Although there are no specific medical treatments for mono, a person can manage symptoms by:

  • getting plenty of rest
  • drinking enough fluids to stay hydrated, with small frequent sips if swallowing is too painful
  • using pain relief medications, including acetaminophen and ibuprofen

It is best to avoid intense physical activity, such as sports or lifting heavy objects.

Learn more about mono treatments.

Here are some answers to common questions about mono.

Is it worse to get mono as an adult?

People ages 15–24 years most often get severe mono, according to a 2015 review.

What is the best cure for mono?

There is no cure for mono, but the virus usually resolves in around 2–4 weeks for most people. Resting, staying hydrated, and taking pain relief medication can help relieve symptoms during recovery.

How do you check for mono?

Doctors often diagnose mono based on symptoms alone. However, blood tests, such as the Monospot test or EBV antibody test, can help doctors confirm a diagnosis.

Symptoms of mononucleosis, or mono, can include an extremely sore throat, severe fatigue, high fever, and swollen glands.

Although uncommon, the liver and spleen may also swell and may stay swollen after the infection recovers.

Other less common symptoms include swollen, painful eyes, a rash, and jaundice.

Symptoms typically develop around 4–6 weeks after exposure to the Epstein-Barr virus and often last 2–4 weeks. Some symptoms, such as fatigue, can persist for months.

Although there are no specific treatments for mono, some remedies can help relieve symptoms. These include staying hydrated, getting plenty of rest, and taking pain relief medication.