Mononucleosis, or mono, does go away. The symptoms usually subside in 2–4 weeks, but sometimes the tiredness lingers for several more weeks. Occasionally, the symptoms may last 6 months or more.

However, the virus that typically causes mono, the Epstein-Barr virus (EBV), does not go away. After mono symptoms get better, the virus stays in the body in a latent or inactive form. Under certain circumstances, EBV can reactivate.

Typically, people get mono only once. When EBV does reactivate, this usually occurs in people with weakened immune systems.

Keep reading to learn when mono goes away, whether there is a cure, and the potential long-term effects.

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Most people feel better from mono in 2–4 weeks. Some may experience tiredness for several more weeks. In some cases, the symptoms linger for 6 months or longer.

No, there is no cure for mono. No specific medications can directly address the cause of mono, which is EBV. There are also no vaccines against EBV.

Mono treatment aims to relieve symptoms. This could involve:

  • getting lots of rest
  • drinking fluids to stay hydrated
  • taking over-the-counter medications for fever and pain

Typically, a person gets mono only once, but some people may get it twice.

EBV is the most common cause of mono. After the initial infection, the virus enters a latent phase, staying in the body in an inactive form.

A 2022 case report shows that reactivation of EBV is rare but possible. When EBV does reactivate, it usually affects those with weakened immunity.

A person could also get mono again due to contracting a different virus. Other viruses that can cause mono include:

  • adenoviruses, a group of viruses that cause colds and flu
  • rubella, the virus that causes German measles
  • cytomegalovirus, a common virus that usually does not cause symptoms unless someone has weakened immunity
  • toxoplasma, a parasite that can cause infection
  • hepatitis A, a virus that causes liver infection
  • HIV

Mononucleosis is a disease that does not usually last longer than a few weeks. However, the virus that typically causes mono, EBV, does stay in the body for life. It most often does not cause any further symptoms once the initial infection ends.

Sometimes, EBV can have long-term effects. These include:

  • Chronic EBV: An older 2015 review states EBV can cause long-term infections in some people. This can lead to chronic symptoms resembling mono, such as lymph node swelling, fever, and an enlarged spleen.
  • Lymphoma: EBV can sometimes lead to lymphoma, which is a type of cancer. There is a particularly strong link between EBV and Burkitt’s lymphoma, and to a lesser extent, Hodgkin’s lymphoma. The correlation varies significantly depending on location, being stronger in areas where malaria is common.
  • Hemophagocytic lymphohistiocytosis (HLH): HLH is a rare, multi-system inflammatory disease that usually affects children. It occurs when the immune system becomes too activated, resulting in organ failure.

It is worth noting that around 95% of people get EBV at some point in their lives, and most do not develop these complications.

The symptoms of mono usually manifest 4–6 weeks after a person contracts EBV. They include:

  • sore throat
  • extreme tiredness
  • headaches
  • body aches
  • fever
  • rash
  • swollen lymph nodes in the neck and armpit
  • less commonly, a swollen spleen or liver

Doctors usually base a mono diagnosis on symptoms. Laboratory tests may not be necessary, but doctors can use them if a person has unusual symptoms or they suspect recurrence.

Below are answers to commonly asked questions about mono.

How do you get mono?

The main means of transmission is contact with saliva. This could occur via kissing or sharing personal items, such as toothbrushes and eating utensils. Other ways of getting it include sex, blood transfusions, and organ transplants.

Is mono an STI?

In some cases, mono is a sexually transmitted infection (STI), since EBV can be present in semen. However, because the primary means of spread is saliva, doctors generally do not classify mono in this way.

When does mono stop being contagious?

Transmission is generally contagious for about 6 months.

Mono usually goes away in 2–4 weeks, but the tiredness may last several more weeks. In some cases, the symptoms may take at least 6 months to disappear.

The virus that usually causes mono, EBV, does not go away. It stays in the body in an inactive form after the symptoms pass, and remains there throughout life.

Medications cannot cure mono, so treatment usually involves rest, hydration, and over-the-counter products to manage pain and fever.

Most humans will get EBV at some point and recover, but it does have links to several long-term health conditions. People who develop severe or unusual symptoms during or after having mono should speak with a doctor.