Symptoms of Gum Sores

Gum sores, also known as mouth ulcers, can come on suddenly and disrupt your life. They can cause pain and sensitivity, especially when you eat and drink.

Gum sores can be caused by irritation or injury, like new braces, a hit to the mouth or a burn. They might also be canker sores or, less commonly, cold sores

Continue reading to learn more about the symptoms of gum sores and when to seek help. 

Woman in the dentist chair with a gum sore

Andrii Bicher / Getty Images

Canker sores appear only in the mouth, most often on the gums or other soft tissues. Cold sores, which are caused by the herpes virus, appear most often on the lips and outside of the mouth. Rarely, however, they can cause gum sores. 


The most common symptoms of gum sores are pain and sensitivity. Here’s how symptoms typically unfold. 

  • Tenderness, burning, and tingling: Oftentimes, before a gum sore is visible, you’ll notice that an area of your mouth is particularly sensitive. However, you likely won’t notice anything visible on your gums yet.
  • A red bump: A day or so after you notice sensitivity, you may see a raised red dot on your gums. This is commonly the first visible sign of a canker sore.
  • A blister-like bump: If your gum sore is caused by a cold sore or hand, foot, and mouth disease, you’ll notice a blister-like sore. A cold sore often appears alone, while hand, foot, and mouth is characterized by many sores. 
  • A white or yellow sore: Canker sores progress into white or yellow sores, often with a red ring around them.

In addition to the physical changes above, you might notice general irritation due to pain and decreased desire to eat or drink if you or your child has a gum sore:

Rare Symptoms

Usually, gum sores are not a cause for concern. They resolve on their own, usually within two weeks. However, if you or your child also experiences these rare symptoms, it’s time to see a healthcare provider. That’s because these symptoms can indicate a more serious underlying medical condition like infection, tooth abscess, or oral cancer.

  • Large white patches inside the mouth: This can be a sign of infection, like thrush, that requires antibiotics to treat. 
  • Drooling or difficulty swallowing 
  • Fever 
  • Sores that last for more than two weeks: In very rare cases, this can be a sign of oral cancer.


Gum sores don’t usually lead to serious complications. However, they may contribute to dehydration, especially in children. That’s because children may avoid eating or drinking, as it makes the pain from their mouth worse. 

Monitor yourself or your child for signs of dehydration, including lethargy, decreased urine output, and dried lips. In addition, help manage the pain with gum sore treatments including over-the-counter pain relievers and topical anesthetics.

When to Seek Medical Care

Usually you won’t need to see a healthcare provider because of gum sores. However, you should reach out to your healthcare provider if you or your child experience:

  • Signs of dehydration
  • Four or more gum sores
  • Swollen, tender, or very red gums
  • A gum sore that’s accompanied by a toothache
  • Fever
  • Swelling of the face or the lymph nodes
  • Sores that last for more than two weeks
  • Bleeding sores

Call 911 immediately if you or your child experience trouble breathing, changes to consciousness, or extreme weakness.


Gum sores are usually not cause for concern. They can be brought on by injury, irritation, and common conditions like canker sores. However, if they’re accompanied by fever or swelling, they could be a sign of serious conditions, including infections or, in rare cases, cancer. It’s OK to wait for gum sores to resolve on their own, but if you have concerning symptoms or sores that last for more than two weeks, talk with your healthcare provider. 

A Word From Verywell

Gum sores are very painful, so it’s natural to want help. Unfortunately, most treatments for gum sores involve managing symptoms. Using over-the-counter pain relievers and topical creams can help, as can avoiding hot, spicy, or acidic foods. If you are struggling with discomfort, reach out to your healthcare provider or dentist for advice. 

Frequently Asked Questions

  • What causes gum sores?

    Gum sores can be caused by irritation, injury, burns, or canker sores. Rarely they can be caused by infection or even cancer. 

  • Are gum sore contagious?

    Gum sores caused by canker sores aren’t contagious. But if your gum sores are caused by an infection like herpes (cold sores) or hand, foot, and mouth disease, they may be contagious.

  • What can I eat with gum sores?

    A bland, cool diet might help decrease gum sore pain when you’re eating or drinking. Avoid anything that’s hot, spicy, or acidic. 

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. MedlinePlus. Mouth sores. U.S. National Library of Medicine.

  2. Nemours. Canker sores.

  3. Nationwide Children’s Hospital. Mouth sores (viral) herpes gingivostomatitis.

  4. Seattle Children’s Hospital. Mouth ulcers.

  5. American Cancer Society. Mouth sores and pain.

By Kelly Burch
Kelly Burch is has written about health topics for more than a decade. Her writing has appeared in The Washington Post, The Chicago Tribune, and more.