Mouth Ulcer

Only those who have had them can understand the exquisitely tender pain caused by a coven of mouth ulcers. Mouth ulcers, canker sores, or if you’re in the mood for ancient Greek, ‘aphthous stomatitis’ affects around 20 per cent of the population. They are generally less than a centimetre in diameter and start life as little red craters that soon fill with pus from white blood cells and bacteria. Mouth ulcers tend to recur, with each episode lasting from 5–7 days.


  • Painful sores on the lining of the mouth.
  • Pain and irritation inside the mouth.

What causes it?

  • Mouth ulcers are reliable signposts of stress – exams, overwork, overtraining, being overwrought, late nights or personal dramas.
  • They can pop up during fevers.
  • Mouth ulcers can indicate a gluten or fluoride intolerance.
  • Mouth ulcers may result from trauma to the inside of the mouth (for example from braces, hard-bristled toothbrushes or chewing the inside of the cheek).
  • Many women find that an outbreak will occur just prior to menstruation when immune levels are at their low point.
  • Mouth ulcers can appear alongside an outbreak of cold sores or oral thrush – both signs that your immune system is below par.

What to do


  • When you have a mouth ulcer, eating a bland diet can help prevent the ouch factor. Although it’s really a case of ‘taste it and see’, in general avoid pepper, chilli, tomatoes, vinegar, lemon, pineapple, mustard, cherries, plums and citrus.
Try cooling foods like watermelon, pear, cucumber, acidophilus yoghurt and lettuce. Bland foods include white rice, steamed chicken breast and white fish.
  • If the ulcers are really bad, live on smoothies for a few days to avoid chewing. Try a banana, raw egg, unsweetened yoghurt, milk (cow, almond, soy or rice), chia seeds and honey, if desired.
  • If you constantly get mouth ulcers and are not under a lot of stress and/or can’t think of any other obvious cause, avoid gluten for a month. If your ulcers disappear in that time, you may be intolerant to gluten.
  • If your immune system is struggling, give it a boost by avoiding sugar, processed carbohydrates, coffee and alcohol.


  • Suck on a combined zinc and vitamin C lozenge every couple of hours.
  • Make a mouthwash using a combination of echinacea, thyme, golden seal and/or calendula. Dilute if using a tincture or if using herbal tea, make it strong. Swill and swallow 3 times a day.
  • Slippery elm is healing for mucous membranes. There are lozenges available containing slippery elm and other healing compounds such as zinc. Suck on these throughout the day.
  • The bee product propolis is healing for ulcers. Dab a little on the ulcers several times a day.
  • Aloe vera gel is healing and blessedly cooling. Apply several times a day.
  • A less acidic environment will temporarily ease the pain, so suck an antacid tablet (from the chemist), or pack your ulcer with paste made from the very alkaline bicarbonate of soda mixed with a little water.
  • Rinse your mouth with acidophilus powder in water each morning to reduce sensitivity and restore healthy microflora to the area.
  • If your ulcers are due to stress, take a strong B group vitamin each day.
  • If your ulcers are a sign your immune system is under par, try a course of Vitamin C and zinc as well as andrographis, echinacea and/or cat’s claw.


  • Although not an allergy, fluoride intolerance may manifest as mouth ulcers. Try a fluoride-free toothpaste for a couple of months to test this theory.
  • If you insist on being heavy-handed with your toothbrush, change to softer bristles or an electric brush and ask your dentist to teach you a gentler brushing technique.
  • Avoid chewing gum; you are tempting fate.
  • Rather than despair over an outbreak, be grateful to your mouth ulcers for showing you that all is not well. Learn to manage your stress before your immune system crumbles further. Try meditation, counselling or belly breathing. See Stress on page 00.

At a glance


  • If your ulcers are severe, drink smoothies for a few days.
  • During an outbreak, stick to foods that are bland and cooling.
  • Trial a gluten-free diet for a month to test whether your ulcers are the result of a gluten intolerance.


  • Every few hours, suck on a combined zinc and vitamin C lozenge, if you find one with slippery elm in it too, all the better.
  • Create a herbal mouthwash (see above). Swill and swallow 3 times a day.
  • If your mouth ulcers are due to stress, take a B-group vitamin twice daily.


  • See your dentist if braces or harsh brushing technique are the cause of your ulcers.
  • If stress is behind your symptoms, treat the cause. Learn to meditate, go to counselling or try belly breathing (see page 00). Find out how to manage your stress and enjoy an ulcer-free mouth.