The NHS says to get checked if you have a mouth ulcer that lasts more than 3 weeks, a red or white patch in your mouth, a lump in your mouth, on your lip or in your neck, or pain, difficulty swallowing or a hoarse voice that is not going away. A GP or a dentist can examine you. These symptoms usually have another cause, but finding mouth cancer early may make it easier to treat.
How we put this guide together: the symptoms, risk factors and next steps come from the NHS, and the self-check advice from the Oral Health Foundation, which runs Mouth Cancer Action Month every November. The practice example uses only what the practice publishes on its own website, checked in October 2026. It is an example, not a recommendation.
Most people think of the dentist as someone who looks after teeth, but a routine dental examination also looks at the soft tissues of your mouth, lips, tongue and throat. Some practices describe this as a mouth cancer screening. Inspire Dental Southend, in Westcliff-on-Sea, for example, sets out on its website what its dentists check and when they refer someone on. This guide explains the signs to look out for, how to check your own mouth at home, what raises your risk and what happens if something needs a closer look.
Signs of mouth cancer to look out for
The NHS lists these as the main symptoms of mouth cancer:
- a mouth ulcer that lasts more than 3 weeks
- a red or white patch inside your mouth
- a lump inside your mouth or on your lip
- pain inside your mouth
- difficulty swallowing
- difficulty speaking, or a hoarse (croaky) voice
- a lump in your neck or throat
- losing weight without trying
All of these are common and are often caused by something far less serious, such as a sharp tooth rubbing the cheek, an infection or a minor injury. The NHS is clear that having symptoms does not definitely mean you have mouth cancer. The point is not to worry about every ulcer, but to notice anything that does not heal or go away, and get it looked at rather than waiting.
What to do about each sign
| What you notice | What the NHS advises | Who can check it |
|---|---|---|
| Mouth ulcer that has lasted more than 3 weeks | Get it checked; do not wait for it to clear on its own | GP or dentist |
| Red or white patch inside the mouth | Get it checked | GP or dentist |
| Lump in the mouth, on the lip, or in the neck or throat | Get it checked | GP or dentist |
| Mouth pain that is not going away | Get it checked | GP or dentist |
| Difficulty swallowing or speaking, or a hoarse voice that does not go away | Get it checked | GP |
At the appointment, the GP or dentist will usually ask about your symptoms, your lifestyle and any other medical conditions, then examine your mouth, neck and jaw. You can ask for someone else to be in the room during the examination if you would like. If they think your symptoms could be cancer, they can refer you urgently for tests or to see a hospital specialist.
How to check your own mouth
The Oral Health Foundation encourages people to check their own mouth, lips, cheeks, head and neck regularly for anything out of the ordinary. You do not need special equipment, just a mirror, good light and clean hands. A simple routine:
- Take out any dentures or removable braces first.
- Look at your lips, top and bottom, inside and out, pulling them gently away from your teeth.
- Check your cheeks by pulling each one out with a finger and looking at the inside lining.
- Look at your tongue, including the sides and underneath, by sticking it out and moving it to each side.
- Check the floor and roof of your mouth by lifting your tongue and tilting your head back.
- Feel your neck and along your jaw for any lumps or swelling that were not there before.
The aim is to know what is normal for you, so you can spot a change. If something looks or feels unusual, especially an ulcer that has not healed in 3 weeks, book an appointment with your dentist or GP.
What raises the risk?
The NHS says it is not always clear what causes mouth cancer, but these things may make it more likely:
- smoking, or chewing tobacco, betel nut or paan
- drinking a lot of alcohol
- having leukoplakia (white patches in the mouth)
- heavy exposure to sunlight or sunbeds, which can cause skin cancer on the lips
- having had cancer before
- a weakened immune system, for example from HIV or from medicines that suppress the immune system
- certain types of human papillomavirus (HPV) infection in the mouth, and changes in your genes
Some practices also list age and family history as factors they take into account when deciding how often to check you.
Ways to lower your risk
You cannot always prevent mouth cancer, but the NHS says you can lower your chances by:
- Stopping smoking. Free help is available through the NHS, including local stop smoking services.
- Stopping chewing tobacco, betel nut or paan.
- Cutting down on alcohol and keeping to no more than 14 units a week.
- Eating a healthy diet, including at least 5 portions of fruit and vegetables a day.
- Exercising regularly.
Lip balm or sunscreen with SPF on your lips also makes sense if you spend a lot of time outdoors, given the link between heavy sun exposure and lip cancer.
What a dental mouth cancer screening involves
A screening is not a separate test with special machines; it is a careful look and feel that a dentist can do as part of a check-up. As a worked example, Inspire Dental Southend's mouth cancer screening page says its dentists:
- ask about your oral health history to identify risk factors
- look at and feel the outside of your mouth, head and neck
- examine the inside of your mouth, including your cheeks and under your tongue
- check your lips, throat, jaw and neck for lumps or swelling
- may examine any lumps or lesions with a handheld scanning device
The same page says it recommends a screening at least once a year, with the schedule based on each patient's risk factors, and that it refers patients to a specialist consultant if findings are inconclusive. The practice's private new patient examination, listed at £35, includes a full oral cancer screening alongside the dental health assessment.
On the NHS, a routine examination is part of a Band 1 check-up, which costs £27.90 in England from 1 April 2026 and is free for some groups, including under-18s and people on certain benefits. If you are not sure whether your dentist checks the soft tissues of your mouth at each visit, ask; it is a reasonable question and a quick one to answer.
What happens if you are referred?
If a dentist or GP thinks you could have mouth cancer, they will refer you to a specialist. The NHS says tests may include:
- a biopsy, where a small sample of cells is taken from the affected area and tested
- scans, such as an X-ray, ultrasound, CT or MRI
Results are usually available within 2 weeks, and a specialist will explain what they mean. If cancer is found, further tests help the team plan treatment, and you will have a specialist team, with a clinical nurse specialist as your main contact. A referral means your symptoms need a closer look; it is not a diagnosis.
Frequently asked questions
How long should a mouth ulcer last before I get it checked?
The NHS advises getting a mouth ulcer checked if it has lasted more than 3 weeks. Most ordinary ulcers heal well within that time.
Should I see a dentist or a GP?
Either can check ulcers, lumps, patches or pain in your mouth. If you have a dentist, they see inside your mouth regularly and may notice changes. For a hoarse voice or difficulty swallowing, a GP is usually the right first step.
Does a dental check-up include a mouth cancer check?
A thorough check-up should include a look at the soft tissues of your mouth, not just your teeth. Some practices describe this as a mouth cancer or oral cancer screening. Ask your dentist if you are not sure.
When is Mouth Cancer Action Month?
The Oral Health Foundation runs Mouth Cancer Action Month every November, focusing on risk factors and the signs and symptoms of the disease.
Sources
- NHS: Mouth cancer symptoms
- NHS: Mouth cancer causes
- NHS: Mouth cancer tests and next steps
- Oral Health Foundation: Mouth Cancer Action Month
- NHS: Understanding NHS dental charges
- NHS Better Health: Quit smoking
General information only, not medical advice. If you are worried about a symptom, speak to your dentist or GP.
