Sore or Swollen Tongue: Common Causes

Your tongue can reveal a lot about your health. Most tongue soreness is minor and heals within days, but some changes point to deficiencies or infections, and sudden swelling can be an emergency.

Imagine your tongue feeling sore and looking unusually smooth and red for weeks. You’re also more tired than usual. A blood test shows low vitamin B12. A few weeks after starting treatment, your energy is back and your tongue feels normal again.

Common causes

• Injury: biting your tongue, burns from hot food, sharp teeth or braces
• Mouth ulcers
• Oral thrush: white patches that may wipe off, leaving red areas
• Geographic tongue: harmless map-like patches that move around
• Vitamin deficiencies: low iron, B12 or folate can cause a smooth, red, sore tongue
• Dry mouth from medicines or dehydration
• Allergic reactions to food, medicines or dental products
• Burning mouth syndrome, more common in women after menopause

Home care

• Rinse with salt water
• Avoid spicy, acidic, very hot or rough foods until it heals
• Keep up gentle brushing and drink plenty of water
• Avoid tobacco and alcohol

But when is it urgent?

Call emergency services if your tongue, lips or throat swell suddenly, especially with difficulty breathing or swallowing. This can be anaphylaxis or angioedema, sometimes caused by blood pressure medicines called ACE inhibitors.

See a doctor or dentist if a sore, lump, ulcer or red or white patch hasn’t healed after three weeks, as this needs checking for mouth cancer. Also get checked for a tongue that stays sore without an obvious cause, or with tiredness or numbness.

Sources: NHS (Sore or white tongue), Cleveland Clinic (Tongue problems), American Dental Association, Mouth Cancer Foundation.