Mucositis is a condition characterised by pain and inflammation of the body's mucous membrane.

The mucous membrane is the soft layer of tissue lining the digestive system from the mouth to the anus.

Mucositis is often divided into two main types, including:

oral mucositis – which can cause mouth ulcers (sores) and pain or difficulty swallowing

gastrointestinal mucositis – which occurs inside the digestive system and often causes diarrhoea

It's also possible for mucositis to affect the lining of the anus – a condition known as proctitis.

Why does mucositis happen?

Mucositis is a relatively common side effect of chemotherapy. It's also sometimes caused by radiotherapy, especially if it involves the head or neck.

Patients receiving radiotherapy for other cancers, such as breast cancer, will not usually develop mucositis, because the therapy is not targeted near the mucous membranes.

The digestive tract is more prone to the harmful effects of chemotherapy or radiotherapy, which can damage the delicate lining.

If you're undergoing cancer treatment that could potentially cause mucositis, you'll be checked regularly for the condition. Mucositis can usually be diagnosed after an examination or a description of your symptoms.

Who is affected?

It's estimated that around 40% of people receiving chemotherapy as part of their cancer treatment will develop some degree of mucositis. It can be more severe in some people, depending on the treatment used.

Mucositis is more common among certain types of cancer. For example, it's estimated that up to 97% of people who have radiotherapy for head or neck cancer will develop some form of mucositis.

About 70% of people receiving high doses of chemotherapy because they are undergoing a stem cell transplant (bone marrow transplant) will develop mucositis.

How is mucositis treated?

The main aim of treatment for oral mucositis is to prevent infection and reduce any pain. This is done by using painkillers and practising good oral hygiene.

Treatments are also available to reduce the symptoms of oral mucositis, such as low-level laser therapy (LLLT) and a medication called palifermin.

Treatment for gastrointestinal mucositis aims to reduce the main symptoms of the condition, such as diarrhoea and inflammation. Treatment includes a combination of medicines and self-care measures.

The symptoms of mucositis should begin to improve a few weeks after chemotherapy or radiotherapy has finished, although it can sometimes take longer.


The most serious cases of mucositis can lead to a number of associated health complications.

Many people with mucositis find it painful to swallow food and require alternative feeding methods, such as a feeding tube.

Also, mouth ulcers can become infected with bacteria. The infection can spread to the blood, then on to other organs. This is known as sepsis and can be life-threatening.

Can mucositis be prevented?

It's not always possible to prevent mucositis, but some treatments can be taken during radiotherapy or chemotherapy to try to reduce the severity of mucositis or how long it lasts. 

Treatments include medications such as palifermin, benzydamine, sulfasalazine and amifostine.


Symptoms of mucositis 

The symptoms of mucositis depend on whether your mouth or digestive system is affected.

Oral mucositis

The symptoms of oral mucositis usually begin five to 10 days after starting chemotherapy, or 14 days after starting radiotherapy.

The tissue inside your mouth will start to feel sore, as if you have been burnt by eating hot food. It's also likely you will develop white patches or ulcers on the lining of your mouth and, in some cases, on your tongue and around your lips.

These ulcers may become very painful and may make it difficult for you to eat, drink or talk. You may also have a dry mouth and a reduced sense of taste. These changes in your mouth can make it more difficult to speak. Relatives and friends may notice your breath smells bad (halitosis).

Milder symptoms of oral mucositis should ease three to four weeks after your course of chemotherapy or radiotherapy has finished. More severe cases will usually require hospital treatment for monitoring and nutritional support.

Gastrointestinal mucositis

The symptoms of gastrointestinal mucositis are more common in people receiving chemotherapy, although they may also occur if you've had radiotherapy to treat cancer in your abdominal (tummy) or pelvic area.

The symptoms of gastrointestinal mucositis usually begin 14 days after you start your chemotherapy or radiotherapy. They can include:


ulcers in your anus and rectum

rectal bleeding, which can cause blood in your stools

passing mucus from your anus (back passage)

abdominal pain

difficulty swallowing (dysphagia)

nausea (feeling sick)


Most of these symptoms will stop a few weeks after your treatment has finished, although occasionally the symptoms of diarrhoea can persist for several months after radiotherapy has finished.

Causes of mucositis 

Mucositis is usually a side effect of cancer treatment.

Radiotherapy and chemotherapy

Radiotherapy and chemotherapy are very effective treatments for killing cancer cells, but can also damage healthy cells, particularly cells in your mucous membrane, which are more vulnerable to damage. The mucous membrane is the soft layer of tissue lining your digestive system, from the mouth to the anus.

Radiotherapy and chemotherapy damage the DNA of the cells on the lining of your mucous membrane, which damages the cells and prevents them from regenerating.

This causes the layer of tissue lining your mucous membrane to eventually break down, and ulcers will form. Your cancer treatment team will make every effort to limit the damage to your mucous membrane, but it's not always possible to prevent damage occurring.

Biological therapies

Biological therapies, also called targeted therapies, are another type of cancer treatment that can cause oral mucositis.

Some cases are thought to be different from mucositis caused by radiotherapy or chemotherapy, although they're poorly understood.  

Increased risk

Certain things can increase your risk of developing mucositis, or may increase your risk of mucositis being severe. These include:  

being younger – oral mucositis is more severe in young people 


drinking alcohol

eating spicy foods


having a dry mouth during your treatment – a dry mouth is another side effect of radiotherapy and chemotherapy

not looking after your mouth properly before and during treatment – for example, by not brushing your teeth regularly 

receiving a higher dose of chemotherapy or being treated with chemotherapy for a long time

receiving high-dose radiotherapy to your mouth or neck

Mucositis can also sometimes develop during and after a stem cell transplant (bone marrow transplant). This is because cancer treatments are used in combination with medicines that reduce the effectiveness of your immune system (the body's natural defence against infection and illness) during this procedure.

Diagnosing mucositis 

Mucositis can usually be diagnosed with a description of your symptoms and after a physical examination.

Oral mucositis

If you're receiving high-dose chemotherapy or radiotherapy, it's likely that you will receive regular (weekly) assessments for mucositis until the risk of developing the condition has passed.

To confirm a diagnosis of oral mucositis, an assessment is made by:

examining your mouth

asking about any symptoms of pain you have

checking you are still able to eat and drink properly

Healthcare professionals use a grading system to determine how serious the symptoms of oral mucositis are. There are several different grading systems available.

The World Health Organization (WHO) uses the grading system described below:

grade one: you're experiencing symptoms of soreness, but there are no ulcers in your mouth

grade two: you have ulcers in your mouth, but are still able to eat solid food

grade three: you're no longer able to eat solid food, but can still swallow liquids

grade four: you're unable to swallow solid foods or liquid

Cases of grade one or two mucositis can usually be treated at home. Cases of grade three and four mucositis usually require admission to hospital so you can be given nutritional support and your general health can be carefully monitored. 

Gastrointestinal mucositis

A diagnosis of gastrointestinal mucositis can usually be made by asking you about your symptoms.

In rare cases, further testing may be required if it's thought that a serious complication has occurred.

For example, a bowel obstruction (blockage) or a perforated (burst) intestine may be diagnosed using a computerised tomography (CT) scan. This is where multiple X-rays are taken at slightly different angles and put together by a computer to create a detailed image of the inside of your body.

Treating mucositis 

There's no single treatment for mucositis, as it largely depends on which type of mucositis you have and exactly what caused it.

For example, effective treatments for oral mucositis caused by radiotherapy may not be helpful if you have gastrointestinal mucositis caused by high-dose chemotherapy.

Oral mucositis


If you have oral mucositis, it's very important you have a good oral hygiene routine, because it can reduce the severity of your symptoms and how long you experience them.

Ideally, you should be assessed by a dentist before starting radiotherapy to the head or neck, or receiving high-dose chemotherapy before a stem cell transplant.

Below is some general advice on good oral hygiene. However, always follow any advice your cancer treatment team gives you if it differs from the advice below:

Brush your teeth every morning and evening, and after every meal. 

Use a toothbrush with soft bristles.  

Replace your toothbrush regularly. Most toothbrushes need to be replaced every three months.

Floss your teeth at least once a day or as advised by your treatment team.

Rinse your mouth five or six times a day using a bland rinse. A bland rinse is a mixture of water and sodium bicarbonate (baking soda) or a mixture of water and salt (to make a saline solution). Your treatment team can advise you on the type of bland rinse suitable for you.

Don't use a mouth rinse containing alcohol.

Avoid tobacco.

Chew gum to help you produce more saliva.

Use a water-based moisturiser to protect your lips.

Make sure you drink plenty of fluids throughout the day to avoiddehydration.


If your mouth is sore because of radiotherapy or chemotherapy, you may need to change your eating habits. The following tips may help you to avoid making your symptoms worse:

eat moist or soft food, because dry food may scratch your mouth – for example, add gravy or sauce to make food easier to swallow

eat plain food

eat warm rather than hot food

Avoid certain foods and drinks including:

acidic fruits – such as oranges and lemons


spicy or salty food

garlic and onions


If you're unable to eat or drink because of mucositis, you may need to be admitted to hospital to receive nutrition.

 Ice cubes 

Sucking ice cubes or ice chips is sometimes recommended as a way of providing relief from the symptoms of oral mucositis.

The healthcare professionals treating you will advise on whether ice cubes could help you.

 Pain relief 

Oral mucositis is often painful, but there are several kinds of painkillers available to try. You may be given painkillers in the form of a mouth rinse, gel or spray.

If a painkiller is not effective, other medicines can be tried alongside it, or a stronger painkiller can be used. Worsening pain does not always mean you'll need to be admitted to hospital, and in most cases you can take the painkilling medication yourself at home.

If a simple painkiller such as paracetamol doesn't work, you may be prescribed a stronger type of painkiller, such as codeine. If this still isn't effective, a stronger opioid can be prescribed, such as morphine.

Non-steroidal anti-inflammatory drugs (NSAIDs) may provide pain relief for some people. However, if you're receiving some types of chemotherapy, NSAIDs could damage your kidneys and affect the way they work. For this reason, only take painkillers as advised by your treatment team.


Palifermin is a type of medication that has proved successful in treating people having a stem cell transplant (bone marrow transplant). This procedure usually includes chemotherapy or radiotherapy.

Palifermin encourages the growth of new cells on the lining of the mucous membrane. This growth is thought to reduce the severity of your symptoms and encourage any ulcers to heal faster. Palifermin also stops sores forming, so can be used to prevent, as well as treat, mucositis.

Palifermin is given by injection. You should receive an injection once a day for three days before your chemotherapy or radiotherapy, and then for three days afterwards, for a total of six doses.

Common side effects of palifermin include:

skin rash, itchiness and redness

an increase in the thickness of the lining of your mouth or tongue

a change in the colour of your mouth or tongue

aching joints

altered taste

Less common side effects include swelling of the mouth or face.

The side effects should pass after you have completed the course of palifermin.

 Low-level laser therapy (LLLT) 

Low-level laser therapy (LLLT) is another treatment that can reduce the severity of oral mucositis. It involves focusing low-energy lasers (beams of light) at affected tissue. LLLT is thought to work by stimulating certain cells that then help to speed up the healing process.

As LLLT requires specialist equipment and training, it may only be available at specialist cancer centres or clinics.

 Infected ulcers 

The mouth ulcers (sores) that mucositis causes can become infected. If this happens, your treatment team may prescribe medication for this. You may also be given a special mouth wash to use to prevent further infections. 

Mucositis may increase the risk of oral thrush, which can be treated with antifungal medicines.


Gastrointestinal mucositis can sometimes lead to diarrhoea, which can be treated in a number of ways, including:

drinking plenty of fluids

oral rehydration solutions

antidiarrhoeal medicines

In severe cases, hospital treatment may be required to administer fluids and nutrients directly into a vein.

 Rectal bleeding and ulcers 

Some people who have high-dose radiotherapy to treat a cancer in their pelvic region may experience rectal bleeding, as well as inflammation and ulceration of the anus and rectum (proctitis).

If these symptoms become severe, they can be treated using medicines such as cinchocaine hydrochloride (proctosedyl)suppositories or hydrocortisone acetate (colifoam). They are both inserted into your bottom and can help relieve pain and inflammation. They contain both a local anaesthetic to numb the area and a corticosteroid to reduce swelling.

Although there's no conclusive evidence to support its use, a medication called sucralfate can be taken for mucositis affecting the upper gastrointestinal tract, such as ulcers developing in your stomach or intestines.

Sucralfate is used to create a protective coating over any ulcers. This may help to prevent further damage and speeds up the healing process. Side effects of sucralfate tend to be mild and short-lasting. They include constipation or diarrhoea, indigestion and nausea.

If you develop a rash or swelling around your face or neck, or shortness of breath, it may indicate that you are allergic to sucralfate. If this happens, you should stop taking the medication and contact your treatment team as soon as possible.

Complications of mucositis 

Oral mucositis and gastrointestinal mucositis can sometimes lead to other problems.

Pain when swallowing

Most people with oral mucositis will experience pain when swallowing. Until your symptoms subside, you may find it easier to switch to a diet containing softer foods, such as mashed potatoes or scrambled eggs.

Feeding tubes may be required in cases severe enough to place you at risk of becoming malnourished and dehydrated. You'll probably be given a nasogastric tube, which is a tube that passes down your nose and into your stomach.

The tube can usually be removed after your ulcers heal and your ability to swallow has returned.


Mouth ulcers can sometimes become infected. This makes them difficult to heal and antibiotics may be needed to treat them.

If you also have a weak immune system and a mouth ulcer becomes infected, there's a risk that the infection will spread in your body. This is known as blood poisoning, or sepsis, and requires urgent assessment and treatment in hospital with antibiotics.

In the most serious cases of blood poisoning, multiple organ damage can cause a large drop in blood pressure. This is known as septic shock and requires immediate treatment in an intensive care unit (ICU). This is so the functions of the body can be supported while the infection is treated using antibiotics or antiviral medication.

Preventing mucositis 

Some treatments can be taken before you receive cancer therapy to try to reduce the severity and duration of mucositis.

However, it's rarely possible to completely prevent mucositis from developing after some cancer treatments.

Oral mucositis


Palifermin is often given to people undergoing high-dose chemotherapyor radiotherapy as a preventative measure against oral mucositis.


Benzydamine may be used if you're having low-dose radiotherapy to your head or neck. Benzydamine has been shown to be reasonably effective in reducing the symptoms of inflammation (swelling) and soreness.

Benzydamine is available in the form of a cream, spray and mouth rinse. Your treatment team will be able to advise you about which type of benzydamine is best for you.

You may experience some stinging and numbness of your mouth when you first start using benzydamine, but these side effects should pass in a few days.

Other treatments

There are other treatments which may be used to reduce the severity of oral mucositis and how long it lasts, although some of these have not yet been tested thoroughly. These include:

sucking on ice cubes or chips, held in the mouth, before, during and after cancer treatment

honey smeared inside the mouth and slowly swallowed to cover as much mucous membrane as possible

aloe vera used as a gel or mouthwash

allopurinol mouthwash

A recent study looking into the effectiveness of a medicine called rapamycin suggested it may be a useful treatment for oral mucositis in the future. However, more research is needed before it can be widely used.

Gastrointestinal mucositis


Sulfasalazine is a medicine that can be used to help reduce inflammation of the digestive system in people having radiotherapy to their pelvis.

Sulfasalazine works by blocking some of the body's chemicals involved in the inflammation process.

Occasionally, some people experience an allergic reaction to sulfasalazine. If you experience any allergy-like symptoms, such as a rash, shortness of breath or swelling of your lips or face, you should stop taking sulfasalazine and contact your treatment team as soon as possible.


Amifostine is a medicine sometimes used to help reduce inflammation of the rectum and anus in people who are having radiotherapy forrectal cancer. It can also be used to reduce symptoms of a dry mouth in people undergoing radiotherapy for head and neck cancer.

Amifostine helps protect healthy tissue by lowering levels of acid in the body, while also providing additional protection against infection.

However, there is currently poor evidence for the effectiveness of amifostine when used to treat mucositis.

Side effects can include:

nausea and vomiting


low blood pressure (hypotension)

Ranitidine or omeprazole

Ranitidine and omeprazole are medicines used to help relieve stomach and gullet pain in people having chemotherapy. They work by lowering the level of acid in your stomach.

Common side effects of ranitidine include: