Mouth Ulcers

Mouth Ulcers

Mouth ulcers, also known as aphthous ulcers, are small, hard sores that appear inside the mouth that are itchy, painful and generally unwelcome.


Small round or oval sores, that appear on your lips, cheeks, floor of your mouth or tongue.


Ulcers are not infectious - so they aren’t caught from other people. Most arise when you damage your mouth - for example by biting your cheek or tongue, or jabbing yourself too hard with a toothbrush. As a result the lining of the mouth tears exposing the nerve underneath - this is why mouth ulcers hurt when you accidentally touch them or food rubs against them. Occasionally mouth ulcers are triggered by stress, hormonal changes (for example, during a woman’s period), or by certain foods such as strawberries or peanuts.

Some people get recurrent ulcers which come every few weeks. If ulcers are frequent it may be caused by a deficiency such as too little iron or B12. Some medications can also trigger ulcers, as can some diseases including Crohn’s disease (which causes inflammation of the gut leading to ulcers in the stomach and mouth) or conditions that attack or suppress the body’s immune system such as HIV.

How are mouth ulcers treated?

Mild ulcers can be treated with over-the-counter mouth ulcer medicines available from your pharmacy. If the problem is more persistent a doctor can prescribe an antimicrobial mouthwash to kill off fungi and bacteria. The most commonly prescribed one is Chlorhexidine gluconate which is used twice daily. If the ulcer is painful a low dose of corticosteroid (steroid) - usually ‘hydrocortisone’ - may be prescribed, taken as a lozenge that dissolves in the mouth. Or a GP can prescribe a painkiller called benzydamine, which comes in the form of a mouthwash or spray, and gets applied directly to the ulcer.

Alternative Remedies & Self-help

To prevent getting mouth ulcers try to avoid becoming run down by eating a healthy, balanced diet, exercising regularly and learning to manage stress effectively. If you are prone to recurrent ulcers, avoid damaging the inside of your mouth by using a softer toothbrush and attend regular dental check-ups.