Why You Get Canker Sores and How To Heal Faster


GETTING A CANKER sore can mean days of distracting discomfort. Canker sores are small, shallow sores that develop on the inside of our lips or cheeks, and they can make it difficult to eat and even talk. Our South San Francisco dentists explain why you get mouth ulcers and what can we do about them.


5 Common Canker Sore Triggers


Most canker sores come from one of these five causes:


  • A tissue injury, such as when we bite our lip or cheek. When it swells up, it compounds the issue by making it easy to accidentally bite it again!

  • Prolonged high stress levels put a real strain on the immune system, which makes the mouth more vulnerable to developing sores.

  • Being sick also strains the immune system, which is why we can be more likely to develop a canker sore in addition to the main infection we’re already fighting.

  • When we eat foods that are highly acidic (including lemons, strawberries, tomatoes, and pineapple), they can be pretty hard on the tissues of the mouth.

  • Ill-fitting dentures or poking braces can lead to canker sores if they rub the cheeks the wrong way.


Simple Remedies for Canker Sores

If you’re prone to canker sores, try to identify the main trigger. Knowing the cause makes it easier to fight back. We can cut back on eating acidic foods, we can use dental wax to protect from poking wires and brackets, and we can work on reducing our stress levels to give our immune systems a break. If none of these solutions apply, or if you’ve tried them and it still isn’t helping, we recommend following these tips:


  • Apply topical medication or take painkillers to reduce the discomfort.

  • Rinse your mouth with warm salt water to help reduce inflammation and make the healing process go faster.

  • Use a toothpaste that doesn’t contain sodium laurel sulfate (but does contain fluoride!).

  • Only brush with a soft-bristled toothbrush to minimize irritation.




Canker Sore Prevention Tactics

Treating a canker sore once it develops is great, but preventing it from ever appearing is even better. Getting plenty of vitamin B12, iron, and folate is a big part of that, and we can get them by making sure to incorporate carrots, salmon, spinach, kale, parsley, and yogurt into our diets.


Maintaining good oral hygiene is important too. Just like being sick can make us more vulnerable to canker sores, having unchecked plaque in our mouths can make it hard for our bodies’ natural defenses to do their jobs in preventing them.


Bring Us Your Canker Sore Questions!

Hopefully we’ve addressed any big questions you have about canker sores here, but if not, we’re happy to answer them! We want our patients to have all the knowledge they need to keep their mouths feeling great.


If it's been more than six months since your last check-up and cleaning or if you have any oral health concerns, schedule your next visit today. Call or text us at (650) 871-1400 or schedule your appointment online.