Glandular fever is a viral illness that mainly affects teenagers and young adults and which persists for several weeks. The main symptoms are fever, sore throat, tiredness, and swollen glands. Treatment focuses on reducing the severity of symptoms.
Glandular fever (infectious mononucleosis or “mono”) is an infectious viral disease that is spread by close person-to-person contact, mainly through saliva. It causes symptoms similar to influenza (the flu) that vary in severity and can persist for several weeks or longer.
Almost anyone, at any age, can catch glandular fever. However, it most commonly occurs in teenagers and young adults. Studies suggest the infection occurs slightly more often in males than in females.
Glandular fever is caused by infection with the Epstein-Barr virus (EBV). Most people will be exposed to the Epstein-Barr virus, and will have developed some degree of immunity to it, by the time they reach adulthood. Many people have no symptoms, which explains why most people have been infected with Epstein-Barr virus by the time they reach adulthood.
After an episode of glandular fever, the Epstein-Barr virus remains in the cells of the body for life. Infection with the virus is usually sufficient to provide long-term immunity from the condition. However, it is possible for the condition to recur. If it does, it is usually in the first year following the initial infection.
Signs and symptoms
The first signs and symptoms of glandular fever may not appear until four to eight weeks after exposure to the virus.
Symptoms are generally at their worst about a week after they first appear, and most symptoms will have resolved within two or three weeks. However, the severity and duration of symptoms can vary considerably between individuals. Symptoms are generally less severe in young children, who may have either no symptoms or only a mild flu-like illness.
The older the person when they develop glandular fever, the more severe the symptoms are likely to be. It is possible for symptoms to persist for several weeks and even for several months.
Initial symptoms commonly include:
- Loss of appetite
- Mental and physical fatigue/weakness
- Aching muscles.
These symptoms are usually followed 2–3 days later by:
- Sore, reddened throat with enlarged tonsils
- Swollen glands in the neck, armpits and/or groin.
Glandular fever can make you feel very tired, and this is usually the last symptom to go away.
In a small percentage of cases a blotchy red rash can occur. Jaundice (yellowing of the skin and whites of the eyes, which is a symptom of an inflamed liver) occurs rarely and, when it does, it generally only lasts 1–2 days.
The spleen is swollen in about 50 per cent of cases. An enlarged spleen is not an immediate health problem but there is a small risk of it rupturing (bursting). A sharp pain in the left side of the upper abdomen may indicate a ruptured spleen and medical attention should be sought immediately.
The doctor will discuss your symptoms and will perform a physical examination. This will include an assessment of whether there is:
- Redness of the throat and swelling of the tonsils
- Enlargement of the lymph nodes
- Enlargement of the spleen
- A rash (especially on the chest).
As these symptoms are so characteristic of glandular fever, they are usually sufficient to make a diagnosis. In some cases, the doctor may take blood tests to check for the presence of the Epstein-Barr virus or to rule out less common but more serious causes of the symptoms, such as hepatitis B or hepatitis C virus infection.
Testing for Epstein-Barr virus to diagnose glandular fever is not necessarily conclusive as it can be difficult to distinguish between a current infection and a past infection.
Treatment and recovery
There is no specific treatment for glandular fever and because it is caused by a virus, antibiotics are of no benefit.
Glandular fever is considered to be a self-limiting infection that resolves with time. Getting plenty of rest and drinking lots of fluid (especially water) to avoid dehydration is very important during recovery.
Pain and discomfort can usually be adequately treated with over-the-counter pain relief medication such as ibuprofen and paracetamol. In severe cases, corticosteroid medication (e.g., prednisone) may be prescribed to reduce pain and swelling of the lymph nodes.
Occasionally the sore throat present with glandular fever can be associated with strep throat, caused by streptococcal bacteria. Antibiotics may be prescribed in these cases in order to combat the bacteria.
An enlarged spleen can be easily damaged. For this reason, it is recommended that strenuous activity and exercise, particularly contact sports, be avoided for at least four weeks after the first symptoms appear, or until the spleen returns to a normal size.
As glandular fever can also cause inflammation of the liver, it is important to avoid alcohol while the condition is present.
Most people with glandular fever recover in two to three weeks. In some cases, however, glandular fever can lead to complications that affect other body systems. These possible complications include:
- Impaired breathing caused by swollen tonsils
- Inflammation of the liver (hepatitis)
- Inflammation of the heart muscle (myocarditis)
- Inflammation of the sac that surrounds the heart (pericarditis)
- Inflammation of the nervous system, including the membranes surrounding the brain and spinal cord (meningitis), the nerves (Guillain-Barre syndrome), and the brain itself (encephalitis)
- Bell's palsy, which is a temporary paralysis of the muscles on one side of the face
- Pneumonia, which may require treatment with antibiotics and/or hospitalisation
- Enlargement of the spleen, which in extreme cases may lead to the spleen rupturing (bursting)
- Destruction of red blood cells leading to anaemia
- Destruction of platelets, which makes people more prone to bruising and bleeding
- Destruction of white blood cells, which may increase the risk of infection.
In some people, glandular fever can lead to symptoms associated with chronic fatigue syndrome . This syndrome leaves the person feeling tired, weak, and listless. The symptoms can continue for an extended period (six months or more) after the infection seems to have cleared, but this is not common.
Most of these complications are rare, occurring in less than one per cent of people with glandular fever.
Glandular fever is not considered to be a highly infectious condition. Nevertheless, steps should be taken to prevent spreading the virus to others.
Because the transmission of saliva from one person to another is the most common way of spreading the Epstein-Barr virus, glandular fever is often called “the kissing disease”. Coughing and sneezing, as well as sharing drink bottles, glasses, cups and eating utensils, can also spread the virus.
People with glandular fever should avoid all of these activities for several days after symptoms have resolved. Regular and thorough hand washing can also help stop the virus from spreading.
The virus remains in the mouth and throat for some time after a person has recovered. They may be infectious for many months after contracting glandular fever. It is advisable, where possible, to avoid close contact with anyone who has, or has recently had, glandular fever.
There is no vaccine against the Epstein-Barr virus to help prevent the spread of glandular fever.
Healthinfo (2018). Glandular Fever (Web Page). Christchurch: Canterbury District Health Board. https://www.healthinfo.org.nz/ [Accessed: 01/04/22]
Mayo Clinic (2020). Mononucleosis (Web Page). Rochester, NY: Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/mononucleosis/symptoms-causes/syc-20350328 [Accessed: 01/04/22]
NHS inform (2020). Glandular fever (Web Page). Glasgow: National Health Service (NHS) Scotland. https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/glandular-fever [Accessed: 01/04/22]
O’Toole, M.T. (Ed.) (2017). Glandular fever. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis: Elsevier.
Reviewed: April 2023