Mononucleosis: Definition, Risk Factors, Causes, Symptoms, Diagnosis, Complications and Treatment

It is a self-limited disease, which means that it usually goes away.

The Epstein-Barr virus causes glandular fever ( infectious mononucleosis ).

This virus can be spread from person to person through close contact (wildly kissing).

It can also be passed on when sharing cups, toothbrushes, etc.

It can take up to six weeks for symptoms to develop after being first infected with this virus.

This is known as the incubation period.

Risk factor’s

Mononucleosis is more common in the young adult and adolescent population.


The immune system produces antibodies during the infection. This generally provides lifelong immunity.

This means that it is rare to have more than one episode of mononucleosis.


The most common virus that causes infectious mononucleosis is the Epstein-Barr virus.

The Epstein-Barr virus is part of the herpes family, containing seven other viruses that infect humans.

Other viruses that can cause illness include HIV, cytomegalovirus, rubella, and hepatitis.

This virus is widespread throughout the world, which means that an individual is likely to contract it at some point in their life.

Most people contract Epstein-Barr virus during childhood.

However, the virus usually causes very mildly or no symptoms in children.

The Epstein-Barr virus can be transmitted through saliva, semen, and blood.

This means that you can catch it even by sharing a glass with an infected person.

Infectious mononucleosis is often referred to as the “kissing disease.”

This is because kissing is the primary method of transmission of the Epstein-Barr virus in young adults and adolescents.

Infectious mononucleosis is caused by the Epstein-Barr virus or cytomegalovirus, members of the herpes simplex virus family.

Cytomegalovirus is a group of viruses in the herpes simplex virus family that often causes cells to enlarge.

When children are infected, they generally do not experience any noticeable symptoms.

However, uninfected adolescents and young adults who contract the virus can develop infectious mononucleosis in nearly 50 percent of exposures.

Mononucleosis symptoms

One or more of the following symptoms commonly occur in about a week.

Symptoms usually set in gradually over another week.

Throat pain

Although this may be mild, the throat is often very sore, red, and swollen.

Glandular fever is generally suspected when severe tonsillitis lasts longer than usual.

Swallowing is often painful, and saliva can collect in the mouth.

A sore throat can be caused by several conditions, from the flu to vocal tension.

A sore throat that occurs suddenly is a typical sign of infectious mononucleosis.

Many patients describe it as the most severe sore throat they have ever experienced.

Swollen lymph nodes

As your body’s immune system fights the virus, it causes the lymph glands to swell.

Any lymph gland in the body can be affected.

However, the glands in the neck are generally the most prominent.

Infectious mononucleosis can cause swollen lymph nodes, becoming quite large and tender.

Cervical lymph nodes in the neck region are most likely to be affected.

Usually, the neck’s lateral and posterior lymph nodes will also grow in size.

This symptom can give the appearance of swelling around the neck.

Flu-like symptoms

Like other viral infections, glandular fever often causes a high temperature (fever), muscle aches, and headaches.

A feeling of severe tiredness often develops with mononucleosis. This is often the last symptom.

Swelling around the eyes

About 1 in 5 people with mononucleosis have swelling around the eyes.

Swollen spleen

This is an organ located under the ribs on the left side of the abdomen.

It is part of the immune system. It swells like the lymph glands and can sometimes be felt under the ribs if you have mononucleosis.

Very occasionally, it causes mild pain in the left upper abdomen.


Severe fatigue can be a symptom of infectious mononucleosis.

Rest, a healthy diet, and avoiding stress can help reduce drowsiness or low energy levels.

Fatigue is generally not relieved by any of these practices and is often accompanied by a severe lack of energy.

Many people become infected with this virus but do not develop symptoms.

This is called subclinical infection. This is more common in children and people over the age of 40.


Infectious mononucleosis can cause a sensation often described as myalgia.

Myalgia is a pain in the muscles or a group of muscles.

These pains tend to appear gradually as the disease progresses.


The Epstein-Barr virus is the most common cause of infectious mononucleosis, yet it can remain inactive in your body for years.

If infection with the Epstein-Barr virus occurs, the body will harbor the virus for the rest of its life.

It can be reactivated without symptoms, and the Epstein-Barr virus can be passed on to other people.

Infectious mononucleosis is usually caused by a primary (first-time) infection with the Epstein-Barr virus.

The condition goes through the following stages:

Epstein-Barr virus-negative

If a person is negative for Epstein-Barr virus infection.

You are unlikely to develop infectious mononucleosis due to the Epstein-Barr virus.


At this stage, you will not experience any symptoms. The incubation period is estimated to last approximately six weeks.

The Epstein-Barr virus begins to reproduce in the mouth. The virus infects B cells, a type of white blood cell.

It can also lodge in the upper exposed area of ​​your tonsils.

Occasionally, the Epstein-Barr virus will move into the blood. However, the precise mechanisms behind this transition are not fully understood.

The development of the disease

As the virus multiplies, your body will start making antibodies against it.

A blood test would show the Epstein-Barr virus’s very high viral load (amount of the virus).

Similarly, there will be a significant increase in white blood cell production.

In this stage, the symptoms of infectious mononucleosis manifest themselves and tend to last around the two-week mark.

However, fatigue and swollen lymph nodes can remain for up to 3 weeks or more.


Infectious mononucleosis is usually a transient condition. This means that the symptoms will go away on their own over time.

However, the disease is a precursor to chronic diseases for some people, usually related to chronic fatigue.

People with lower rates of physical activity tend to be more prone to this problem.

The patient can still infect other people with the Epstein-Barr virus and remain contagious for an average of up to six months after the infectious mononucleosis outbreak.

Mononucleosis Diagnosis

The symptoms caused by mononucleosis are similar to those caused by other viruses.

Therefore, it can be challenging to diagnose mononucleosis with just a doctor who examines you.

Therefore, a blood test can detect a particular antibody and confirm if you have mononucleosis.

This will reveal if heterophile antibodies are present, indicating that the Epstein-Barr virus is active.

A blood test for infectious mononucleosis will also look at the activity of your lymphocytes (white blood cells).

A very high number of lymphocytes and a positive heterophile result will probably confirm the diagnosis.

If your blood test is negative, but your doctor suspects you have mononucleosis, you may have a blood test several weeks later.

Unusual symptoms and complications

Most people with mononucleosis do not have complications or unusual symptoms. If complications do occur, they can include:

Damaged spleen

This is a severe but rare complication. A damaged spleen can occur after having mononucleosis.


In some people with mononucleosis, a generalized red rash occurs that is not itchy.

This usually wears off quickly.


Sometimes mononucleosis causes mild inflammation of the liver that causes a yellowing of the skin (mild jaundice).

Malaise and depression

It is common to feel tired and low for the duration of the illness and a week or so afterward.

Some people develop “post-viral fatigue” for varying periods.

Other complications of infectious mononucleosis that do not occur often can include:

  • Kidney inflammation.
  • Hemolytic anemia.
  • Nervous system problems, such as encephalitis, meningitis, and other conditions.
  • Inflammation of the heart muscle.
  • Heart rhythm problems
  • Upper airway obstruction.

Treatment for mononucleosis

Treatment is primarily focused on controlling and reducing your symptoms.

Infectious mononucleosis can cause extreme fatigue and a general feeling of being unwell (sick).

Most doctors recommend adequate rest as the condition runs its course.

Usually, no specific treatment is needed. However, it is essential to drink plenty of fluids.

Staying hydrated is essential for general well-being.

However, drinking enough water should be a priority when you are sick.

Lack of fluid intake leads to dehydration, especially if you also have a high temperature.

Mild dehydration can make headaches and tiredness worse.

Your doctor will likely recommend taking acetaminophen or ibuprofen to relieve general pain, headache, and fever.

The spleen can swell while you have infectious mononucleosis.

In rare cases, it can break suddenly or due to external trauma.

Your doctor will likely recommend avoiding contact sports, such as hockey or basketball, for the duration of the illness.

To prevent spread, kissing and close body contact with other people should be avoided while sick.

It is also best not to share cups, towels, etc., while you are sick.

If you drink alcohol when you are sick with mononucleosis, you may feel much worse than usual due to the effect of mononucleosis on your liver.

Antibiotic medications are not usually used, as a virus causes glandular fever.

Occasionally, an antibiotic will be prescribed if a secondary throat infection is caused by a germ (bacteria) that responds to antibiotics.