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.
  2. It spreads mainly 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. Not everyone infected with the virus gets symptoms and many people have had glandular fever at some time without knowing.
  6. 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?

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.

How is glandular fever spread?

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.

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. 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

How is glandular fever treated?

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.

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)
  • 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, 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.

How do I avoid spreading glandular fever?

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.

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

Reviewed by

Dr Li-Wern Yim is a travel doctor with a background in general practice. She studied medicine at the University of Otago, and has a postgraduate diploma in travel medicine (Otago). She also studied tropical medicine in Uganda and Tanzania, and holds a diploma from the London School of Hygiene & Tropical Medicine. She currently works in clinical travel medicine in Auckland.

Credits: Health Navigator Editorial Team. Reviewed By: Dr Li-Wern Yim, Travel Doctor, Auckland Last reviewed: 13 Jul 2020