Glandular fever

Also known as infectious mononucleosis or 'mono'

Key points about glandular fever

  • Glandular fever is a common infectious condition most often caused by the Epstein-Barr virus and generally seen in teenagers and young adults.
  • It spreads mainly through saliva, which is why it's sometimes called the 'kissing disease'. 
  • Symptoms can include fever, sore throat, sore glands and tiredness.
  • Most people get better in 2–4 weeks, but you may feel tired for several months.
  • Not everyone infected with the virus gets symptoms and many people have had glandular fever at some time without knowing.
  • See your doctor if you have the symptoms because if it's not treated, there can be complications.
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Usually symptoms of glandular fever appear 4–6 weeks after you get infected with the Epstein-Barr virus. Symptoms may develop slowly and may not all occur at the same time.

  • Tiredness – a feeling of intense tiredness often develops with glandular fever. 
  • Sore throat – although this may be mild, your throat is usually very sore, red and swollen. Glandular fever is typically suspected when tonsillitis is severe and lasts longer than usual. Swallowing is often painful and saliva may pool in your mouth.
  • Flu-like symptoms – like other viral infections, glandular fever often causes a high temperature (fever), muscle aches and headaches. It can make you feel quite unwell.
  • Swollen glands around your neck – as your body's immune system fights off the virus it causes your lymph glands to swell. Any lymph gland in your body can be affected. However, the glands in your neck are usually the most prominent. They can become quite large and tender.
  • Swelling around your eyes – about 1 in 5 people with glandular fever become quite puffy and swollen around the eyes. This goes in a short time.

Not everyone infected with the virus gets symptoms and many people have had glandular fever at some time without knowing. Most people get better in 2–4 weeks, but some people may feel tired for several more weeks. Occasionally, the symptoms of glandular fever can last for 6 months or more.

Many people in the community have the Epstein-Barr virus. It is spread mainly by close contact with saliva (spit) or nasal (nose) secretions of infected people. This can happen by touching hands, or sharing toys, eating utensils and drink bottles or by kissing. However, these viruses can also spread through blood and semen during sexual contact, blood transfusions and organ transplantations.

Only some people who are exposed to the virus get the symptoms of glandular fever. If you do get symptoms, you can be infectious for up to 7 weeks beforehand, and for many months after your symptoms go away.

If you have a sore throat and fever that has lasted for more than a few days, you should see your doctor or nurse for advice. In many cases, your doctor will be able to make a diagnosis based on your history and examination. In some situations, blood tests may be required to help confirm the diagnosis.

Image credit: Canva

There is no specific medical treatment for glandular fever. Treatment focuses on reducing symptoms until recovery and includes: 

  • medicines for pain and fever, eg, paracetamol or ibuprofen
  • warm salt water gargles
  • plenty of rest
  • drinking lots of fluids, especially water
  • avoiding strenuous activities and exercise
  • gradually increasing activity levels as you are able to.

As glandular fever is caused by a virus, antibiotics won't be effective. You may need to reduce some of your normal activities for a while. Getting enough rest and sleep is important but complete bed rest is not recommended as it can make the symptoms of fatigue last longer.

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Most people with glandular fever will have few, if any, long-term complications other than fatigue. However, there can be complications. These include:

  • damaged spleen – this is rare and is usually a result of contact sport
  • a lower level of blood cells, such as anaemia
  • an infection, such as pneumonia
  • a neurological illness, such as Guillain-Barré syndrome or Bell's palsy
  • a widespread red (not itchy) rash and other skin conditions
  • a mild inflammation of your liver causing yellowing of your skin (mild jaundice)
  • post-viral fatigue, where you feel low and tired.

Most people get better in 2–4 weeks. However, glandular fever can cause tiredness and loss of energy for up to a few months.

  • You can return to work, university or school as soon as you feel well enough.
  • There is little risk of spreading the infection to others as long as you follow precautions, such as not kissing other people or sharing utensils and good hand hygiene.
  • Avoid contact sports or activities that put you at risk of falling. This is because if you have a swollen spleen, a sudden knock could cause it to rupture.
  • You also need to avoid alcohol as this could damage your liver, which is often affected by the infection.

If you develop glandular fever, avoid kissing and sharing eating and drinking utensils after your symptoms begin. You also need to take extra care with washing your hands regularly, particularly after coughing or sneezing.

Avoid close contact with anyone who has, or has recently had, glandular fever. Try not to kiss, share cups, cutlery or towels with other people. Good hand hygiene prevents the virus spreading. Make sure you thoroughly wash your hands regularly.

You do not need to be isolated from others, because most people will already be immune to the Epstein-Barr virus.

From sick and tired of being tired and sick – laboratory investigation of glandular fever(external link) BPAC, NZ, 2012:

Liver function tests do not need to be routinely tested. If they are, 80% will be abnormal as the liver is often affected.

  • When testing is indicated, the recommended tests are a full blood count (FBC) and a heterophile antibody test, followed by serology if the diagnosis remains unclear (or pregnancy, older or immunocompromised)
  • If jaundice or significant hepatomegaly, check liver function tests
  • Throat swabs - a positive throat swab for Strep does not exclude glandular fever. (30% with primary glandular fever infection have asymptomatic Strep carriage.

Other resources

Infectious mononucleosis(external link) Dermnet NZ, 2007
Glandular fever(external link) Health Info, NZ, 2018
Glandular fever(external link) Patient Info, UK, 2016
Candy B, Hotopf M. steroids for symptom control in infectious mononucleosis.(external link) Cochrane Database of Systematic Reviews 2006, 3: CD004402. 


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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Li-Wern Yim, Travel Doctor, Auckland

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