Glandular fever

Also known as infectious mononucleosis or 'mono'

Glandular fever is a common infectious condition most often seen in teenagers and young adults.

Key points

  1. Glandular fever is most often caused by the Epstein-Barr virus, a type of herpes virus.
  2. It spreads through saliva, which is why it is sometimes called the 'kissing disease'. 
  3. Symptoms can include fever, sore throat, sore glands and tiredness.
  4. Most people get better in 2–4 weeks, but you may feel tired for several months.
  5. See your doctor if you have the symptoms because if it's not treated, there can be complications.

What are the symptoms of glandular fever?

Symptoms can include:

  • flu-like symptoms such as fever and headache
  • sore throat (often with white stuff on your tonsils)
  • swollen lymph glands (such as in your neck)
  • feeling generally unwell
  • joint pains
  • tiredness
  • loss of appetite.

Not everyone gets symptoms and many people have had glandular fever at some time without knowing.

How is glandular fever spread?

Many people in the community have the Epstein-Barr virus. It is spread by close contact with saliva (spit) or nasal (nose) secretions of infected people. This can happen by touching hands, toys, eating utensils, drink bottles or by kissing.

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

How is glandular fever diagnosed?

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. If the symptoms and signs are typical, the diagnosis can be made based on your history and examination. If your doctor isn't sure, you may be asked to have a blood test to help confirm the diagnosis.

What is the treatment for glandular fever?

Treatment focuses on reducing symptoms 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. Complete bed rest is no longer recommended, as it can make the symptoms of fatigue last longer.

Are there any complications with glandular fever?

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) – this is not serious and quickly goes
  • post-viral fatigue, where you feel low and tired.

What is the prognosis for glandular fever?

Most people get better in 2–4 weeks. However, it 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 for 2 months, such as not kissing other people or sharing utensils.
  • Avoid contact sports or activities that put you at risk of falling 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.

How do I avoid spreading glandular fever?

If you develop glandular fever, avoid kissing and sharing eating and drinking utensils for at least 2 months after your symptoms begin. You also need to take extra care with washing your hands regularly, particularly after coughing or sneezing.

 It's important to 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.

Learn more

Glandular fever NHS, UK


  1. Sick and tired of being tired and sick: laboratory investigation of glandular fever BPAC, NZ, 2012
  2. Infectious mononucleosis Dermnet NZ, 2007
  3. Glandular fever Health Info, NZ, 2018
  4. Glandular fever Patient Info, UK, 2016
Credits: Health Navigator Editorial Team.