If you’ve ever had a canker sore (also called aphthous ulcers), you know how painful and bothersome they can be. These small, fluid filled blisters or sores can appear anywhere around your mouth, but you’re most likely to find them on your tongue, lips, gums or the inside of your cheeks. They can bother you with a tingling or burning sensation when you eat or drink, or feel sore all the time.
Canker sores seem similar to cold sores (fever blisters), but they aren’t quite the same. “Canker sores are not contagious and are not caused by a virus,” said Mari Ricker, MD, an integrative medicine specialist with Banner Health. Cold sores, on the other hand, appear on the outside of the mouth rather than the inside and they’re caused by the herpes simplex virus, so they are contagious.
You might notice a burning or tingling feeling before a canker sore appears. Then you’ll see a small red bump that will open and turn white or yellow with a red border. After it appears, you might feel pain when you’re eating, drinking or talking.
Canker sores fall into two main types:
- Simple canker sores may happen three to four times a year. They usually heal quickly.
- Complex canker sores are less common but more severe. They can last longer and be more painful.
Canker sores are common. When you understand what triggers them, how to prevent them and how to treat them, you can keep canker sores from having a big impact on your life and your well-being.
Why do you get canker sores?
“We do not know exactly what causes canker sores, but there are several different culprits,” Dr. Ricker said. “There are also things that might make you more likely to get them.”
Here are some factors that have been linked with canker sores and could be responsible for causing them. These factors don’t always cause canker sores, and they don’t cause canker sores in everyone.
- Cuts or scrapes in your mouth from braces, dental work or biting your lip or cheek
- Emotional or physical stress
- Changes in your hormones, like when you have your menstrual period
- Some foods and drinks – mainly things that are hot, acidic (like citrus fruits and tomatoes), spicy foods or scratchy (like chips)
- Low levels of nutrients like vitamin B12, zinc, iron and folate
- Allergic reactions to food, toothpaste or mouth care products
- Medical conditions like celiac disease, inflammatory bowel disease or immune disorders
- Family history – you may be more likely to get canker sores if other people in your family get them
- Immune system reactions to bacteria or viruses in your mouth
- Brushing your teeth forcefully
- Smoking and using tobacco, which can irritate your mouth
How to prevent and treat canker sores
There are a few steps you can take to make it less likely you’ll get a canker sore:
- Brush your teeth regularly and carefully using a soft-bristle toothbrush to help keep your mouth clean
- Manage stress
- Eat a balanced diet
- Avoid triggers as much as possible
Even if you’re careful, you might still get a canker sore. If you do, there are products you can buy over-the-counter (OTC) in pharmacies, grocery stores and big box stores that may help treat them. These products come in gels, ointments and mouth rinses.
“Treatment should focus on reducing the discomfort from the sores and keeping them from getting irritated so that they can heal quickly,” Dr. Ricker said. “Numbing gels, like we use for kids who are teething, can help with the pain. And avoiding trigger foods and irritants can allow your body to heal the area.”
You can also rinse your mouth with salt water and put honey or aloe vera gel on the painful sores.
“The mouth is very good at healing because it has a lot of blood flow. So even though you may have a sore, you probably won’t have a scar once it has healed,” Dr. Ricker said.
When to get medical care
Most of the time, canker sores heal with home treatments and OTC medicines in a week or two. Contact a health care provider if your mouth sores:
- Last longer than a few weeks.
- Keep coming back.
- Are large — bigger than a pencil eraser.
- Are very painful.
- Appear when you have a fever, swelling in the mouth, diarrhea or abdominal pain.
A provider can diagnose canker sores based on how they look and your medical history. If you have severe or complex canker sores, your provider may want you to try prescription medications or mouthwashes.
The bottom line
Canker sores are common sores that appear inside your mouth. They are different from cold sores, which appear outside of your mouth. Cold sores are also contagious, while canker sores are not.
You can take steps to prevent canker sores and watch out for things that trigger them. If you get canker sores, they can be uncomfortable or painful, but they usually heal in a week or two with home treatment.
If you’re concerned about canker sores, you can connect with a health care provider for guidance. To talk to an expert about caring for your mouth, reach out to Banner Health.
