Mouth cancer is where a tumour develops on the surface of the tongue, lips, gums or jaws.

The main causes of mouth cancer are drinking heavily and smoking or chewing tobacco. The risk is greater if you do both.

Other things may also increase the risk. These include:

  • Chewing betel quid (even if it doesn’t have tobacco in it)
  • Medical problems that cause a weak immune system
  • infection with a virus called human papilloma virus (HPV)
  • Eating an unhealthy diet with not enough fresh fruit and vegetables.
  • Long-term ultraviolet light exposure (from sunlight, sun beds or sunlamps) increases the risk of lip cancer.

The most common symptom of mouth cancer is an ulcer or sore in the mouth or on the lip that doesn’t heal.

Other symptoms may include:

  • A white (leukoplakia) or red (erythroplakia) patch in the mouth that doesn’t go away
  • A lump or thickening in the mouth or on the lip
  • difficulty or pain with chewing, swallowing or speaking
  • Bleeding or numbness in the mouth
  • Bad breath (halitosis)
  • loose teeth or dentures that don’t fit well anymore
  • a lump in the neck
  • losing a lot of weight over a short time.

These symptoms can be caused by other conditions, but it's important to have them checked by your doctor or dentist. Mouth cancer can be treated more successfully when it’s diagnosed early.

Read more about diagnosing and treating head and neck cancer at UCLH.