What Causes Canker Sores in the Mouth?

Wouldn’t it be great if you were canker sore-free? This page will tell you about the causes of canker sores. By altering your lifestyle and avoiding things that can potentially trigger canker sores, you can significantly reduce your chances of getting canker sores.

It’s worth noting that none of these causes of canker sores has been proven, but they are generally thought to cause canker sores.


Stress seems to affect every facet of our lives, and canker sores are no exception. Canker sores have been closely linked to prolonged and/or intense stress. Stress is one cause that most doctors agree with. Canker sores tend to form when you face increased stress. The irony is that this just makes your stress worse! Experts say that simply avoiding stress can help canker sore outbreaks.

Trauma to the mouth

This can be caused by something as simple as a toothbrush, dentures, or braces.  Any small abrasion or sore inside the mouth can turn into a canker sore.  The initial sore caused by the trauma is not a canker sore until it becomes infected.  Canker Free helps speed the healing process and assists in preventing the wound from forming into a canker sore.

Food sensitivities

You may get canker sores due to food sensitivities and allergies. For example, many people get canker sores after eating high volumes of acidic foods, such as pineapples and oranges.


Some medical professionals believe that your tendency to get canker sores can be influence by heredity. Unfortunately, there’s not much you can do about this cause.

Vitamin or mineral deficiencies

Low levels of B1, B2, B6, B12, iron, folic acid, L-Lysine and vitamin-C are often cited as potential causes of canker sores.

Poor dental hygiene

Suffice it to say, keep good care of your teeth and gums lowers the risk of irritation.

Toothpaste containing SLS

Avoid toothpaste with SLS to prevent aggravating your canker sore.

Most toothpastes on the market contain a substance called SLS (Sodium Lauryl Sulfate) This substance is known to cause and inflame canker sores by attacking the mucous membranes in the mouth.  If your toothpaste contains SLS, we recommend you stop using it now; even toothpastes labeled “natural” usually contain SLS.

Baking soda and SLS free toothpastes are good alternatives.