Mono: what are the early signs and symptoms?

Mono: what are the early signs and symptoms?

Mononucleosis, commonly called "mono," is an illness caused by the Epstein-Barr virus. Although it's rarely serious, mono can cause bothersome symptoms that last several weeks.

The Centers for Disease Control and Prevention (CDC) say that 90 percent of people worldwide have had an infection with Epstein-Barr virus (EBV) at some point in their lives, but many of them had no obvious symptoms when they were ill.

Others, particularly older adults, may not have "classic" symptoms of mono at all. This makes mono a difficult disease to diagnose in certain age groups.

Symptoms of mono in different age groups

The symptoms of mono vary widely among different ages of people. Adolescents and young adults have the most classic symptoms.

After first catching mono, there are no symptoms for 4 to 8 weeks. This is known as the incubation period. The virus is in the body but hasn't yet made the person feel sick. However, people may be able to spread mono to others during this time.

Once the incubation period is over, symptoms may appear quickly. The illness may be severe for a few days and gradually get milder as it runs its course. The types of symptoms vary widely among different age groups.

Teens and young adults

People aged 15-24 are most likely to develop the main symptoms of mono, according to the American Academy of Family Physicians. They also tend to have the most severe symptoms. The symptoms can last for several days or longer and may include:

Common symptoms of mono include a sore throat and swollen glands in the neck.

  • Extreme tiredness
  • High fevers
  • Headache
  • Body aches
  • Red, sore throat
  • Swollen glands in the neck or underarms
  • An enlarged spleen
  • A pink, measles-like rash

Symptoms may last 1 to 2 weeks, but some people may be sick for longer. Fever, sore throat, and other common symptoms may last for several days and then gradually get better.

Tiredness tends to be the longest-lasting symptom. It can sometimes last for weeks or months after other symptoms have gone.

Researchers don't know for sure why teens and young adults have the most severe symptoms. A study in Clinical and Translational Immunology suggests that people in this age group may have more exposure to the virus during deep kissing. This higher exposure to another person's saliva could make a person iller.

Young children

The same study suggests that many children may get the virus from their parents. The researchers believe parents may accidentally spread it to children when the virus reactivates in the parent. The amount of virus spread from a parent's past infection may be lower, however, causing fewer, milder symptoms in a child.

If a child has mild mono symptoms, a parent may think their child has a cold or flu. This may be the case if fever and sore throat are the main symptoms.

Older adults

A study in Age and Ageing states that mono is much less common in adults over 40. Adults may not show the most well-known symptoms of red throat and swollen glands.

Instead, older adults may be more likely to have liver problems, according to an article in American Family Physician. A fever with liver inflammation can make mono harder to spot in this age group. Muscle aches may also be more common in this group.

Possible complications of mono

Serious problems from mono are very rare.

Spleen rupture may occur in 0.5 percent of patients and is potentially fatal. Luckily, this is very uncommon. Symptoms of a spleen rupture include:

Spleen rupture can cause pain on the left side of the chest.

  • Pain in the upper left belly
  • Pain in the left shoulder that feels worse when breathing in
  • Pain in the left chest area
  • A sudden drop in blood pressure, which may cause fainting, confusion, dizziness, or paleness

Getting hit in the belly near the spleen may cause a swollen spleen to rupture. For this reason, athletes should avoid contact sports for at least 3 to 4 weeks after getting mono.

Mono can also cause liver problems. People may also get jaundice. This means that the whites of their eyes or their skin can look yellow. In the majority of cases, the liver inflammation will improve on its own as the body clears the infection.

In rare cases, mono can also cause:

  • Blood problems such as anemia or low platelet counts
  • Inflammation of the heart muscle
  • Inflammation of the brain and spinal cord membranes, known as meningitis
  • Encephalitis - inflammation of the brain
  • Guillain-Barre syndrome
  • Breathing problems due to swollen tonsils

Most people never have any of these problems. Those who have weakened immune systems may be more likely to have these complications. This includes people with HIV or AIDS, those undergoing some kinds of cancer treatment, and people who have had an organ transplant.

How do people get mono?

The virus that causes mono is most often spread through saliva, which is why it's called the "kissing disease."

Mono can be spread in other ways, however. Sharing drinks, toothbrushes, or anything that touches the mouth and saliva can spread mono from person to person. Mono may also be spread through sexual contact, blood transfusions, and organ transplants.

According to the CDC, many people catch mono during childhood. In some cases, they may not realize they have it. Children often don't show classic symptoms, or only have mild symptoms that are confused with a common cold or the flu.

Once a person has caught mono, the virus stays in the body forever. The virus may then reactivate at a later time. This doesn't make a person feel sick, but the person will be able to spread mono to others during this time through their saliva - even if they had mono years ago. As a result, someone may catch mono from another person who doesn't appear to be sick at all.

Diagnosing mono

Doctors may be able to diagnose mono with a physical exam, especially in young people who have common symptoms.

Because children and older adults tend to have less obvious symptoms, a physical exam alone may not be enough. In these cases, additional testing may be needed. Blood tests can identify whether or not a person has had a recent or past infection with EBV.

Treatment and prevention of mono

Because mono is a virus, antibiotics do not work against it. There is no vaccine for mono, though experts are working on one. There is no known way to "cure" mono, so doctors recommend managing symptoms until a person feels better. This may include:

Rest and medication can help manage the symptoms of mono.

  • Pain relievers and fever reducers such as acetaminophen or ibuprofen
  • Salt water gargles for a sore throat
  • Plenty of rest
  • Avoiding sports until symptoms are gone

There is no proven way to prevent mono, but a few simple tips can help avoid it:

  • Washing hands after using the bathroom and before eating
  • Coughing or sneezing into a sleeve or tissue and washing hands afterward
  • Avoiding people who have mono or who have symptoms of mono until they recover
  • For those with symptoms of mono, staying home from work or school
  • Not sharing objects that come into contact with the mouth

When to call a doctor

Many illnesses cause fever and sore throat, particularly colds, flu, and common viruses.

As mono is easily confused with other illnesses, any unknown or worrisome symptoms may warrant a call to the doctor to rule out other problems.

The American Academy of Pediatrics advise parents to call the doctor if a child:

  • Is extremely fussy or drowsy
  • Has a severe headache or sore throat
  • Develops a rash without obvious cause
  • Has a seizure
  • Has a temperature of 100.4°F or higher for children under 3 months of age
  • Has a temperature above 104°F for any age

Those with symptoms of a ruptured spleen should seek emergency care immediately.


Although mono symptoms may interfere with life for several days or weeks, most people get better without any long-term problems. Managing symptoms with self-care and rest is often the best way to deal with this illness.

What Are The Signs And Symptoms Of Mono (Video Medical And Professional 2018).

Section Issues On Medicine: Disease