Mouth Sores: Tracking Ulcers and Triggers

Low iron, vitamin B12 and folate are the deficiencies most often linked to recurrent aphthous ulcers, and low zinc is sometimes implicated. These can appear before anemia shows up, so blood tests are reasonable if ulcers keep returning. Coeliac disease can cause the same deficiencies by impairing absorption, which is why some clinicians check coeliac serology too. Log how many ulcers you get each month, how long each lasts, plus fatigue, hair changes, heavy periods and any restrictive eating, since that pattern is what makes a clinician order the right blood panel rather than a general one.

Repeated ulcers in one fixed location usually point to local trauma rather than a systemic cause. A sharp tooth edge, a chipped filling, an ill-fitting denture, an orthodontic bracket or a habit of biting one cheek will break the same patch of lining again and again. A dentist can smooth or adjust the culprit and the ulcers often stop. If the site keeps ulcerating with no obvious mechanical cause, or the lesion never fully heals between episodes, it needs examination. Log the exact location each time, since a consistent spot versus scattered spots is a genuinely useful distinction.

Canker sores (aphthous ulcers) sit inside the mouth on soft, moving tissue such as the inner lip, cheek or under the tongue. They are round or oval with a white or yellow center and a red border, they are not contagious, and they usually clear in one to two weeks. Cold sores are caused by herpes simplex virus, start as a tingle then a cluster of blisters that crust over, and appear on the lip border or the skin around the mouth, sometimes on the hard palate or gums. Cold sores are contagious, especially while weeping. Logging the exact site helps separate the two.

The practical rule is two to three weeks. A single ulcer that has not healed by then should be examined, particularly if it is firm at the edges, painless, on the side of the tongue or floor of the mouth, or associated with a neck lump, numbness or a loose tooth. These features warrant a check for oral cancer, and risk is higher with smoking, chewing tobacco, betel quid or heavy alcohol use. Also seek advice sooner if ulcers come with fever, genital ulcers, eye inflammation, joint pain, bloody stools or unexplained weight loss. Note the start date so the three-week mark is clear.

Bring dates for each episode over the past six to twelve months, the number and size of ulcers, where they sat, how long they took to heal, and whether any scarred. Add anything that lines up: exam stress, acidic foods, a toothpaste change, cycle days, new medications, and any bowel, skin, eye, joint or genital symptoms. Photos of a current ulcer help. Trace Health charts your severity logs against food, sleep, stress and medication entries and exports a doctor-ready PDF, so the recurrence pattern is visible in one page rather than reconstructed from memory.