Cold Sores vs. Canker Sores: What Are They and How Do I Get Rid of ‘Em?


Cold sores and canker sores are common conditions that occur in both children and adults. More than half of the population has had to deal with these, and many don’t know the difference between the two or how to treat them.

Cold sores and canker sores both appear in or near the mouth, but they are very different. Here’s how to tell them apart, treat them, and prevent them. 

What Are Cold Sores?

You might know cold sores by their nickname: “fever blisters.” They are a symptom of an infection caused by herpes simplex virus type 1, which is why they are also known as oral herpes.

“Oral herpes is not commonly sexually transmitted like its counterpart, genital herpes, which is caused by herpes simplex virus type 2. Oral herpes is generally contracted during childhood or young adulthood from nonsexual contact with saliva,” explains Michael P. Rosenthal, MD, Chief of Family Medicine and physician at Penn Family Medicine Pennsylvania Hospital.

If you’ve been infected with cold sores before, the virus can remain in the body and come back again if it is triggered. Things that can trigger cold sores include:

  • Cold, fever, or flu
  • Excessive sun exposure
  • Stress
  • Hormonal changes, such as menstrual cycles and pregnancy
  • Trauma to the face, such as cuts or facial surgery

How Do I Know If I Have Cold Sores?

Cold sores are called oral herpes because the virus is located in and around the mouth. They usually appear as a painful blister or group of blisters on the:

  • Lips
  • Gums
  • Roof of mouth
  • Tongue

These sores can itch, burn, tingle, and drain fluid throughout the duration of the infection, which lasts about 7 to 10 days.

“A physician can examine your cold sores and make a diagnosis based on the clinical appearance. If there is uncertainty, a swab of the fluids from the sores can be tested for herpes simplex virus type 1. In most circumstances medications are not needed, but antiviral therapy may be prescribed for severe or recurring cases,” says Dr. Rosenthal.

Are Cold Sores Contagious?

Unfortunately, cold sores are highly contagious. One of the most common ways people develop cold sores is simply by coming into contact with another infected person. You can become infected this way even if that person is treating their symptoms and regardless of whether they are experiencing any symptoms at all.

Children and young adults are the most vulnerable to the virus because they are most likely to spread the virus through kissing and sharing eating utensils.

People with cold sores can spread it until their sores are completely scabbed over.

To stay safe from cold sores or keep others safe from your own cold sores:

  • Don’t kiss people when you have an outbreak.
  • Avoid close contact with others when you have an outbreak.
  • Avoid contact with people who have weakened immune systems, like newborn babies or people being treated for cancer, when you have an outbreak.
  • Don’t share personal items, like lip balms, razors, toothbrushes, or towels.
  • Don’t share food and beverages.
  • Don’t touch your cold sores.
  • If you touch your cold sores, wash your hands immediately.
  • Wash your hands often.

What Are Canker Sores?

Canker sores are small, round ulcers that appear inside your mouth. Like cold sores, they can appear alone or in clusters. The exact cause of canker sores is unknown, but there are several things than can trigger an outbreak.

Canker sores are often agitated by:

  • Food allergies
  • Stress
  • Hormone changes
  • Vitamin deficiencies
  • Infections
  • Hot, spicy foods

How Do I Know If I Have Canker Sores?

“If you have canker sores, you may notice one or more small, round sores with red edges and a gray, white, or yellow center,” explains Dr. Rosenthal. These sores may appear in several different areas in your mouth, including:

  • Inside your lip
  • Inside your cheek
  • Under your tongue
  • At the back of your throat

Canker sores can be very painful, but usually go away on their own in about 1 to 2 weeks.


How to Get Rid of Cold Sores and Canker Sores

Both types of sores tend to heal on their own within 2 weeks. There aren’t any cures for cold sores or canker sores, but there are many treatments that can help speed up the healing process or prevent them altogether.

Treating Cold Sores

Cold sores can be treated with ointments, lip balms, and sunscreen. These treatments can help slow the spread of the virus and relieve your symptoms. Lip balms and sunscreens can even be used to prevent cold sores when you don’t have them.

If your sores are particularly painful, pain relievers can be used. Try to avoid acidic foods that may irritate the sores. You can also keep them cool by using cold towels, ice, and cooling ointments.

Treating Canker Sores

“Canker sores are most often treated with ointments, creams, and mouth rinses. These treatments should help reduce the pain, slow down the outbreak, and make outbreaks less frequent,” Dr. Rosenthal advises.

As with cold sores, avoiding hot and spicy foods can both prevent canker sores from developing and treat their symptoms. Pain medications can also be used to relieve pain when necessary.

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