Many people experience sores in their mouths, but they often confuse cold sores with canker sores. Understanding the differences can help you seek appropriate treatment and reduce discomfort.

What Are Cold Sores?

Cold sores, also known as fever blisters, are caused by the herpes simplex virus (HSV). They typically appear on the outside of the mouth, especially around the lips. Cold sores are contagious and can spread through close contact like kissing or sharing utensils.

They often start as small, fluid-filled blisters that eventually break open, forming a crust. Cold sores usually recur in the same area and may be triggered by stress, illness, or sunlight.

What Are Canker Sores?

Canker sores are small ulcers that develop inside the mouth, on the cheeks, gums, or tongue. Unlike cold sores, they are not caused by a virus and are not contagious. The exact cause of canker sores is unknown, but factors such as stress, minor mouth injuries, nutritional deficiencies, and certain foods can contribute.

Canker sores appear as round or oval white or yellowish ulcers with a red border. They can be painful, especially when eating or talking, but they usually heal on their own within one to two weeks.

Key Differences at a Glance

  • Location: Cold sores are on the outside of the mouth; canker sores are inside the mouth.
  • Cause: Cold sores are caused by herpes virus; canker sores have no known viral cause.
  • Contagious: Cold sores are contagious; canker sores are not.
  • Appearance: Cold sores are fluid-filled blisters; canker sores are ulcers.
  • Recurrence: Cold sores tend to recur in the same area; canker sores usually heal completely.

When to See a Doctor

If you experience frequent or severe sores, or if they do not heal within two weeks, consult a healthcare professional. Antiviral medications can help reduce cold sore outbreaks, while topical treatments can alleviate pain from canker sores.

Proper diagnosis is important to ensure appropriate treatment and to rule out other oral conditions. Remember, maintaining good oral hygiene and avoiding known triggers can help manage both types of sores.