Important: This page is for general information only and is not a diagnosis. If you are worried about a symptom, please see a doctor.

What is a persistent mouth ulcer?

A mouth ulcer is a small, painful sore inside the mouth — on the inner cheeks, lips, tongue, gums, or roof of the mouth. Most mouth ulcers are harmless and heal on their own within 1 to 2 weeks. They are usually caused by a minor injury (like biting the cheek), stress, a vitamin deficiency, or a sharp tooth or denture. A persistent mouth ulcer is one that does not heal within 3 weeks — and this type always needs a doctor’s attention.

When is a mouth ulcer a warning sign?

Most mouth ulcers are not cancer. But certain features should make you take the ulcer seriously and see a doctor promptly:

  • The ulcer has not healed after 3 weeks, even without obvious injury or irritation
  • The ulcer is painless — pain is common with ordinary ulcers; a painless ulcer lasting weeks is more concerning
  • There is a red patch (erythroplakia) or white patch (leukoplakia) in the mouth that cannot be rubbed off
  • There is a lump or thickening in the mouth, cheek, gum, or jaw
  • You have difficulty chewing, swallowing, or moving your tongue or jaw
  • Your lip or jaw feels numb or tingly without explanation
  • A sore throat that does not go away or a feeling that something is stuck in the throat

In Bihar, oral cancer is strongly linked to chewing tobacco in any form — gutka, khaini, and paan masala — as well as smoking bidi and cigarettes. If you use any of these and have a mouth sore lasting more than 3 weeks, please see a doctor without delay.

Other possible causes

Not every persistent ulcer is cancer. Other causes of mouth ulcers that can last several weeks include:

  • Canker sores (aphthous ulcers) — recurrent, painful, usually heal in 1–3 weeks
  • Herpes simplex (cold sores) — caused by a virus, can recur on lips or gums
  • Dental irritation — a rough tooth, broken filling, or ill-fitting denture rubbing the same spot
  • Nutritional deficiencies — low iron, vitamin B12, or folate can cause slow-healing ulcers
  • Infection — fungal infections (oral thrush) or bacterial infection
  • Inflammatory conditions — such as lupus, Crohn’s disease, or Behcet’s disease

Even if you think the ulcer has an obvious cause, any sore lasting more than 3 weeks should be evaluated by a doctor or dentist to rule out a serious cause.

Warning signs that need prompt attention

See a doctor as soon as possible — do not wait weeks — if you have:

  • A mouth sore or ulcer lasting more than 3 weeks
  • Any red or white patch in the mouth that appeared without an obvious cause
  • A lump or swelling in the mouth, jaw, or neck that is growing or has been there for more than 2 weeks
  • Unexplained bleeding from the mouth
  • Difficulty swallowing that has lasted more than 2 weeks
  • A sudden change in the fit of your dentures
  • Loose teeth without dental disease

What a doctor will do

When you visit a doctor or dentist with a persistent mouth ulcer, they will:

  1. Ask about your symptoms — how long the sore has been there, whether it is painful, and your tobacco and alcohol use
  2. Examine the mouth carefully — looking at the ulcer’s size, colour, edges, and whether it bleeds easily
  3. Feel the lymph nodes in your neck — swollen lymph nodes can be a sign that an infection or cancer has spread to nearby tissue
  4. Recommend a biopsy if needed — a biopsy is a small tissue sample taken from the edge of the ulcer and sent to a laboratory to look for cancer cells. A biopsy is the only way to confirm whether an ulcer is cancer. It is a brief procedure done under local anaesthetic and is not as scary as it sounds
  5. Order further tests if the biopsy confirms cancer — CT scan or MRI to see if it has spread

If you are not comfortable seeing a doctor straight away, a dentist or ENT (ear, nose, and throat) specialist can also examine the mouth and refer you to the right specialist.

Where to get help in Bihar

If you live in Bihar and have a mouth sore that will not heal, the following centres can help:

  • Mahavir Cancer Sansthan, Phulwarisharif, Patna — Bihar’s main cancer hospital; has oral and head-and-neck cancer specialists
  • AIIMS Patna — has an ENT and head-and-neck oncology outpatient department
  • Nearest government district hospital — your first step; can examine and refer you appropriately

See our full hospital directory at /find-care/hospitals/.

In India, you can call 1800-22-1951 (Indian Cancer Society helpline, free) for guidance on where to go. For emergencies, call 108 or 112.