What is tonsillitis?

Tonsillitis is an infection of the tonsils.
Tonsils are the two oval-shaped soft tissue structures that are located at either side of the back of the throat. They help your body fight infections as they form part of the immune system (the body’s defence system). When the tonsils are infected, they become enlarged, red, swollen (inflammation) and sometimes produce pus (fluid from the tonsils that appear as yellow, white, or grey spots or coatings). Tonsillitis can be:

  • Acute – this is a short-lived infection (often lasting up to 7 days)
  • Chronic (recurrent) – this is where the infection is persistent,
    sometimes as a result of repeated episodes of acute tonsillitis

How common is tonsillitis?

  • Tonsillitis is very common and is mostly seen in children aged between 5-10 years and young adults between 15 and 25 years
  • This is because tonsils grow during early childhood (whilst other body defences are not yet fully formed), and then in most people start to become smaller as they age
  • By adulthood, most people’s tonsils are very tiny or will have disappeared nearly completely
  • The most common symptom is a sore throat, but it is only one of many different causes of a ‘sore throat’

What causes tonsillitis?

Tonsillitis can be caused by either a virus or a bacterium (germs).

  • Viruses account for up to 80% of all cases
  • Different viruses and bacteria may present with different signs or symptoms
    • This can sometimes help give a clue as to what type of germ is causing the infection.
    • Which can help indicate who may benefit from antibiotics (as
      antibiotics only work on bacteria)


  • If a virus is the cause, the infection tends to have milder symptoms
    and is often related to the common cold
  • Some viruses that can cause tonsillitis are adenovirus, rhinovirus, and
  • These are the same viruses that can cause the common cold


  • The most common group of bacteria that can cause tonsillitis are
    called ‘group A streptococcus’
  • This causes a condition called ‘strep throat’ and can result in more
    severe symptoms
  • This group of bacteria also causes ‘Scarlett Fever’ (an infection
    mainly seen in children, which presents as a bright red rash on the
    body, a sore throat and fever)

What increases your risk of getting tonsillitis?

  • Age: 5-10 years and 15 and 25 years
  • Children of parents who smoke (giving up smoking is advised)
  • Having a low immune system (immune deficiency)
  • If tonsillitis occurs in other family members
  • A personal or family history of atopy (hay fever, asthma, and eczema)

Is tonsillitis infectious?

Infectious means that you can pass on an infection to someone else. The viruses and bacteria that can cause tonsillitis can be passed on to others, as they are usually picked up as part of daily life e.g. close contact with people, coughing and sneezing. Therefore, if you have tonsillitis you should avoid social contact, which involves staying at home, especially if you’re unwell.

What symptoms can you get with tonsillitis?

Symptoms commonly come on over a period of 2-3 days and then gradually reduce, usually by 7 days. Your symptoms may present as:

  • Sore throat
  • Pain on swallowing
  • Tiredness
  • Feeling hot/chills
  • Headache
  • Pain in your ears or neck
  • Abdominal (tummy pain – especially in young children)

If the infection is caused by:

  • A common cold virus, additional symptoms may include coughing,
    sneezing and a runny/blocked nose
  • The ‘Epstein-Barr virus’, this can cause a condition known as ‘Glandular Fever’ (infectious mononucleosis), this tends to cause severe tonsillitis as well as other symptoms. It most commonly affects teenagers
  • The flu virus (influenza), additional symptoms may include weakness, muscle aches and a dry cough

What signs can you get with tonsillitis?

  • What signs can you get with tonsillitis?
  • Redness of your throat including tonsils.
  • Enlarged swollen tonsils.
  • Yellow, white, or grey spots or coatings on your tonsils.
  • A high temperature.
  • Swollen glands (lymph nodes) in your neck.
  • If the infection is caused by the ‘group A streptococcus’ bacteria, classical
    signs and symptoms are:
    • A rapid onset.
    • Headache.
    • Abdominal pain.
    • Pain on swallowing (dysphagia)
    • Foul-smelling breath
    • Feeling quite unwell
    • No cough
    • Tender and enlarged glands in your neck
    • A rash occurring 1 to 2 days after the onset of symptoms (may indicate Scarlett Fever)
    • The rash consists of widespread small red raised bumps (which look like goosebumps) on your body that may
      be itchy

How do you diagnose tonsillitis?

Some people with a ‘sore throat’ do not seek medical attention, as their symptoms are often mild and go away on their own.

However, if you do seek medical advice, and if tonsillitis is the cause,
it can be diagnosed clinically. This means it is based on your symptoms, signs, and a clinical
examination. To help identify tonsillitis and the underlying cause your healthcare
professional can do the following:

  • Take a history from you, which involves asking you about your symptoms
  • Examine you:
    • Your throat – look for inflammation (redness and swelling)
      and any pus on your tonsils
    • Your neck – to check for swollen neck glands
    • Checking for fever – as most people with acute tonsillitis have a fever over 38°C

For young children, your healthcare professional may ask about the number of wet nappies, fluid intake and check for signs of dehydration. Your healthcare professional will then use certain criteria to determine the likelihood of a tonsilitis bacterial ‘streptococcal’ infection (and therefore the need for antibiotic treatment).

Do you need a throat swab?

  • A throat swab is when a little stick with a small ball of cotton wool on the end is placed into your mouth at the back of your throat
  • The aim is to obtain tonsillar pus for testing
  • Throat swabs are not currently recommended for everyone as evidence is not strong enough to support their use. 
  • However, throat swabs may be done if you are:
    • Vulnerable (very old or young)
    • Have a low immune system
    • Have very severe symptoms

What other tests could you have?

  • You may be asked to have a blood test if you fall into the following groups:

    • There is a suspicion that you may have a low immune system. 
    • Are a teenager or young adult with severe tonsillitis. This is to help check if you have ‘glandular fever’, which is a common cause of tonsillitis in that age group.

How is tonsillitis treated?

  • Most cases of tonsillitis will resolve on their own at around 7 days without any treatment or intervention. But the following measures can be used to help:


    • Rest. 
    • Keeping hydrated by drinking an adequate amount of fluids
    • For pain relief and/or fever: 
      • Paracetamol
      • Ibuprofen – can also help but may not be suitable for you (e.g. if you have asthma or kidney problems).
      • Always check the labels to see if these medications are suitable and ensure you do not exceed the recommended dosage and follow instructions
    • Medicated lozenges may help reduce pain (in adults)
    • Salt-water gargling for throat pain relief
    • Other things you may try (but there is no good evidence to suggest will help) includes:
      • Mouthwashes
      • Non-medicated lozenges
      • Local anaesthetic mouth spray
    • Hot drinks should be avoided as these can exacerbate pain

Do I need antibiotics?

FeverPAIN Score

  • Fever
  • Pus or white spots on the tonsils
  • Symptoms for less than three days
  • Severely inflamed tonsils
  • No cough or cold-like symptoms 

1 point for each

Centor criteria

  • Pus or white spots on the tonsils
  • Swollen neck glands
  • History of fever (greater than 38°C)
  • No cough 

1 point for each

If you have a FeverPAIN score of 4 or 5 OR a Centor score of 3 or 4 you will be offered immediate antibiotics. This is because you are most likely to have a bacterial infection. 

Alternatively, you can be offered: 

  • A back-up antibiotic prescription. This is where you do not need to take the antibiotics immediately and are instead taken if your symptoms don’t improve in 3 to 5 days, or your symptoms worsen

If you have a FeverPAIN score of 2 or 3: you may also be given a back-up antibiotic prescription. Again, these are taken if your symptoms don’t improve in 3 to 5 days, or your symptoms worsen

If you are very unwell or have a high risk of developing complications (e.g. you have a low immune system):

  • Antibiotics are offered immediately

Common examples of antibiotics used for tonsillitis include:

  • Phenoxymethylpenicillin – this is the first-choice antibiotic
  • Clarithromycin – can be used if you are allergic to penicillin
  • Erythromycin – can also be used if you are allergic to penicillin

A 5 – 10 day course of antibiotics is usually enough to treat the infection

When should you return to school or work?

You can return to work or school after your fever has resolved and you are no longer feeling unwell, and/or after taking antibiotics for at least 24 hours.

What about surgery to remove the tonsils?

If you or your child has recurrent (chronic) tonsillitis that is affecting everyday life such as:

  • Needing time off from work or school

  • The tonsils become so swollen that swallowing is impaired

Assessment by a specialist ear, nose, and throat doctor is advised in order to discuss removing the tonsils (tonsillectomy)


Recurrent (chronic) tonsillitis is defined as:

  • 7 episodes in the last year OR 

  • 5 episodes per year for the last two years OR

  • 3 episodes per year for the last 3 years


  • Is a very common operation, with 2 out of 3 operations in the UK performed on children

  • There are different surgical methods that can be used, but the specialist doctor will discuss the best options

  • Removing the tonsils helps:

    • Reduce the number of episodes of a sore throat (though it does not prevent other non-tonsillitis related causes of a sore throat)

    • Improve sleep quality in children (as enlarged and chronically infected tonsils can interfere with a child’s sleep)

  • Although tonsils help the body fight infections, if you need to have your tonsils removed you will still be protected from infections by the rest of your immune system

What other conditions can be associated with tonsillitis?

  • Glandular fever – this commonly affects teenagers. They may be quite unwell with very extreme tiredness and large pus-filled tonsils
  • Coxsackievirus – which is a virus that causes small blisters to develop on both the roof of the mouth and the tonsils. After a few days, these blisters erupt and then a scab forms, which may be very painful
  • Herpes simplex virus (the virus that also causes cold sores) – this infection occurs commonly in adolescents and young adults

When the infection spreads from the tonsils to other nearby tissues it can cause the following:

    • Peritonsillar abscess (quinsy) – this is where pus builds up next to the tonsil. It is uncommon and needs immediate medical attention. Symptoms may include fever, neck pain, reduced opening of the jaw, a muffled voice, and an enlarged, displaced tonsil. It is most common in children 2 to 4 years of age
    • Retropharyngeal abscess – this is where pus builds in the back of the throat. Symptoms may include a visible neck swelling, reduced opening of the jaw and a severe sore throat that does not get better after a few days. This needs immediate medical attention
    • Ear infections

It is important to always seek medical attention if you are unsure about you, or your child’s symptom