Glandular fever (infectious mononucleosis) is a virus infection that most often affects teenagers and young adults. Although it can make you feel quite ill, full recovery is usual. It is a self-limiting illness which means it usually goes away by itself.
What is glandular fever?
Glandular fever (also known as kissing disease) is a viral infection usually caused by the Epstein-Barr virus. This virus can be passed from person to person by close contact (especially kissing).
It can also be caught by sharing cups, toothbrushes, etc. It can take up to seven weeks for the symptoms to develop after a person has first been infected with this virus. This is called the incubation period.
What are the symptoms of glandular fever?
One or more of the following symptoms commonly occur for about a week or so. Symptoms then usually gradually settle over another week.
Although this may be mild, your throat is usually very sore, red and swollen. Glandular fever is typically suspected when a tonsillitis is severe and lasts longer than usual. Swallowing is often painful and saliva may pool in your mouth.
As your body's immune system fights off the virus it causes swollen lymph nodes (glands). Any lymph gland in the body can be affected. However, the glands in the neck are usually the most prominent. They can become quite large and tender.
Like other viral infections, glandular fever often causes a high temperature (fever), muscle aches and headaches. It can leave you feeling unwell.
A feeling of intense tiredness often develops with glandular fever. This is often the last symptom to go.
Swelling around eyes
About 1 in 5 people with glandular fever become quite puffy and swollen around the eyes. This goes in a short time.
The spleen is an organ under the ribs on the left side of the tummy (abdomen). It is part of the immune system. Like the lymph glands, it swells and can sometimes be felt below the ribs if you have glandular fever. Very occasionally, it causes mild pain in the upper left abdomen.
Many people become infected with this virus but do not develop symptoms. This is called a subclinical infection. This is more common in children and in those aged over 40 years.
What causes glandular fever?
Glandular fever is most often caused by the Epstein-Barr virus (EBV). In about 1 in 10 people with glandular fever, it is caused by a different virus, such as cytomegalovirus, adenovirus or human herpesvirus 6.
The virus infects the cells on the lining of the throat. The infection is then passed into the white blood cells before spreading through the lymphatic system. This is a series of glands (nodes) found throughout your body that allows many of the cells that your immune system needs to travel around the body. The lymphatic system also includes certain organs such as the spleen.
Is glandular fever contagious?
Glandular fever is not particularly contagious. It is mainly spread through contact with saliva, eg kissing, sharing cups, food and drinks, toothbrushes or cutlery.
Small children may be infected by chewing toys that have been contaminated with the virus. It can also be spread through sexual contact, blood transfusion and organ transplant.
The disease is contagious during the incubation period and while symptoms are present. Some people may remain contagious for up to 18 months after they have had the infection.
Who gets glandular fever?
Glandular fever can affect people of any age but is most commonly affects teenagers and young adults. The immune system makes antibodies during the infection. This then usually provides lifelong immunity for those who develop glandular fever. This means that it is rare to have more than one episode of glandular fever.
How is glandular fever diagnosed?
The symptoms caused by glandular fever are similar to symptoms due to various other viruses. Therefore, it can be difficult to diagnose glandular fever just by a doctor examining you.
So, a blood test is commonly done that can detect a particular antibody and confirm if you have glandular fever. If your blood test is negative but your doctor suspects you have glandular fever then you may have your blood test repeated a few weeks later.
Glandular fever complications
Most people with glandular fever do not have complications or rare symptoms. If complications do occur, they may include:
This is a serious complication of glandular fever but rare, occurring in about 1 in 100 cases. The spleen is an organ under the ribs on the left side of the tummy (abdomen). A swollen spleen is more delicate than normal.
A damaged spleen may occur if the left side of the chest or abdomen is injured - for example, after a fall. The spleen normally settles down to its normal size after about three weeks.
However, one study found that in 3 out of 19 people it took eight weeks. Therefore, if you want to be absolutely sure, you should avoid contact sports such as rugby for eight weeks after having glandular fever.
A widespread, non-itchy red rash occurs in some people with glandular fever. This usually fades quickly.
The Epstein-Barr virus commonly causes mild inflammation of the liver which gets better by itself and often has no symptoms. About 1 in 20 people develop yellowing of the skin (mild jaundice). This also goes away without treatment in the vast majority of cases.
Malaise and depression
It is common to feel tired and low for the duration of the illness and for a week or so afterwards. About 1 in 10 people develop 'postviral fatigue' which can last for several months. . This usually clears in time.
Glandular fever treatment
There is no cure for glandular fever and usually, no specific treatment is needed, as your immune system deals with the infection by itself. However:
Drink plenty of fluids
It is important to drink plenty of fluids. It is often tempting not to drink very much if it is painful to swallow. This can lead to mild lack of fluid in the body (dehydration), particularly if you also have a high temperature (fever). Mild dehydration can make headaches and tiredness much worse. It can be worthwhile taking paracetamol or ibuprofen to ease pain, headache and fever.
Some studies have looked at the use of steroid medicines for people with glandular fever. The theory was that steroids help to reduce inflammation in various conditions and so may do so for glandular fever. However, there is currently not enough evidence to recommend the use of steroids to treat people with glandular fever.
To prevent spread, you should avoid kissing and close body contact with other people whilst you are ill to stop glandular fever spreading. It is also best not to share cups, towels, etc, whilst you are ill. There is no need to miss any school if you have glandular fever, unless you feel unwell. You should see your doctor if any unusual, severe or unexplained symptoms develop.
Reduce alcohol intake
If you drink alcohol when you are unwell with glandular fever, you can feel much worse than usual because of the effect of glandular fever on the liver. You should therefore not drink any alcohol if you have glandular fever until you are better.
Antibiotic medicines are not usually used, as glandular fever is caused by a virus. Antibiotics do not kill viruses. Occasionally, an antibiotic is prescribed if you develop a secondary throat infection that is caused by a germ (bacteria) which does then respond to antibiotics.
How long does glandular fever last?
A full recovery is usual within a couple of weeks. Some people have a lingering tiredness that lasts a few weeks, sometimes longer. It is rare to have glandular fever again.
Further reading and references
Glandular fever (infectious mononucleosis); NICE CKS, July 2021 (UK access only)
Rezk E, Nofal YH, Hamzeh A, et al; Steroids for symptom control in infectious mononucleosis. Cochrane Database Syst Rev. 2015 Nov 8(11):CD004402. doi: 10.1002/14651858.CD004402.pub3.
Dowd JB, Palermo T, Brite J, et al; Seroprevalence of epstein-barr virus infection in u.s. Children ages 6-19, 2003-2010. PLoS One. 2013 May 228(5):e64921. doi: 10.1371/journal.pone.0064921. Print 2013.
Katz BZ, Shiraishi Y, Mears CJ, et al; Chronic fatigue syndrome after infectious mononucleosis in adolescents. Pediatrics. 2009 Jul124(1):189-93.
Kang MJ, Kim TH, Shim KN, et al; Infectious mononucleosis hepatitis in young adults: two case reports. Korean J Intern Med. 2009 Dec24(4):381-7. doi: 10.3904/kjim.2009.24.4.381. Epub 2009 Nov 27.