Canker Sores: Swords That Don’t Kill—but Sure Do Hurt

You know the feeling. A tiny sore starts brewing inside your mouth; before you know it, every sip of coffee or bite of a sandwich feels like you’re chewing glass. Canker sores—those small, painful ulcers that show up inside your cheeks, on your lips, or under your tongue—might be harmless, but they’re anything but forgettable. Let’s unpack what they are, what causes them, and how I help patients find relief when one of these sneaky little swords shows up.

What Are Canker Sores?

Canker sores (also known as aphthous ulcers) are small, round or oval lesions that form inside the mouth's soft tissues. Unlike cold sores, they’re not contagious and don’t appear on the outside of your lips. They often have a white or yellow center with a red halo—and yes, they hurt way more than their size suggests.

They typically last 7 to 14 days, and while they usually go away on their own, they can make eating, drinking, and talking feel like a battle.

What Causes Them? (It’s Complicated)

The short answer?  We don’t always know. But here are the most common triggers I’ve come to learn:
- **Stress** – Your immune system can flare in response to anxiety or lack of sleep.
- **Minor mouth injuries** – Accidentally biting your cheek or brushing too hard.
- **Acidic or spicy foods** – Think citrus, tomatoes, vinegar, hot sauces.
- **Nutritional deficiencies** – Especially B12, iron, folate, or zinc.
- **Hormonal changes** – Many women experience more canker sores during menstruation.
- **Autoimmune issues** – Canker sores can be a symptom of inflammatory or GI conditions like celiac or Crohn’s disease.
- **Toothpastes with sodium lauryl sulfate (SLS)** – This common foaming agent can be irritating for some.

In my practice, we treat the whole person—not just the sore—so we explore these possibilities together.

What You Can Do About It

When one of these painful ulcers shows up, I recommend a few tried-and-true remedies:
- **Rinse with warm salt water** or a mild baking soda solution to soothe the area.
- **Use over-the-counter topical gels** like benzocaine (with caution—some people are sensitive).
- **Switch to SLS-free toothpaste** if you’re prone to flare-ups.
- **Avoid acidic or spicy foods** until it heals.
- **Consider a multivitamin** or B12 supplement if you’re consistently getting them.
- **Manage stress**, sleep well, and stay hydrated—your immune system will thank you.

In persistent or severe cases, I may prescribe a steroid rinse or refer you to a specialist for deeper evaluation.  And no, you're not being dramatic—canker sores are real, painful, and worth treating with care.

When to See Me or Your Primary

If your canker sores last more than two weeks, appear unusually large, recur frequently, or are accompanied by fever or swollen glands, please don’t ignore them.  While most are benign, there are rare conditions that mimic canker sores and deserve a closer look.  That’s where I and most probably your primary come in—not just to treat what you see, but to ensure we’re not missing what you don’t see.

A Kind Word for the Sore in Your Smile

Canker sores may not be dangerous, but they’re disruptive.  And they remind you that even small things can significantly impact your daily life.  Don't suffer in silence if you’re dealing with one (or many).  I’m here to help—with solutions, support, and a warm smile that doesn’t sting.