With both conditions so common, it’s no surprise that many people confuse them. Both can make eating, drinking, brushing your teeth, and even talking feel uncomfortable or even embarrassing.

Although their names sound alike, canker sores and cold sores are not the same at all. Knowing the difference is important because it changes how you treat and prevent these mouth lesions.

For Cold Sores Dermatologists often recommend over-the-counter options like Blistex Cold Sore Treatment Docosanol Cream 10%, which contains the FDA-approved ingredient Docosanol Cream (10%) to provide soothing relief and support healing. Canker sores can be treated with an ADA-accepted liquid or gel, like Kank-A.

In this article, we’ll compare canker sore vs cold sores and learn about what causes them and the best treatment options available.

Quick Comparison: Canker Sores vs Cold Sores

Here’s a quick comparison to help you see the main differences between canker sores and cold sores at a glance:

Feature	Canker Sores	Cold Sores
Cause	Not caused by a virus; exact cause unknown (can be triggered by stress, injury, or certain foods)	Caused by herpes simplex virus (HSV-1)
Contagious?	Not contagious	Very contagious
Where they appear	Inside the mouth (gums, tongue, cheeks, inner lips)	Outside the mouth, usually on or around the lips
Appearance	Small, oval, or round sores with a white or yellow center and red border	Fluid-filled blisters that break open, scab, and then heal
Types	Minor: Small Ulcers, Less than 1 cm, No Scarring Major: Ulcers Larger than 1 cm, Painful, Can Cause Scarring Herpetiform: Tiny clusters, 10-100 at a time, can merge into irregular ulcers.	Mostly one type: Appears in small clusters of fluid filled blisters that burst out.  HSV-1 typically causes oral herpes (cold sores) spread through oral contact like kissing or sharing drinks; however, it can also cause genital herpes through oral-genital contact. HSV-2 primarily causes genital herpes and is usually spread through sexual contact; it tends to recur more often than HSV-1.
Symptoms	Tingling/burning before the sore, pain while eating, drinking, or talking	Tingling/itching before the blisters, painful blisters, cracked lips, scabs
Treatment	Occlusive agents (e.g., Kank-A® Mouth Pain Liquid), local anesthetics, mouthwashes, and NSAIDs.	Over-the-counter creams (e.g., Blistex Cold Sore Treatment Docosanol Cream 10%), oral antiviral drugs, and pain relief medications.

Causes of Canker Sores and Cold Sores

Canker sores and cold sores look similar, but they have different causes. Let’s take a look at what causes these mouth sores.

Canker Sores

According to the National Institute of Dental and Craniofacial Research (NIDCR), canker sores are not contagious. You can’t get them by making contact with someone who has them. That said, the exact cause of canker sores isn’t known. 

However, several factors are believed to play a role:

• Minor injuries: Imagine biting your cheek during lunch. This kind of small injury can spark a canker sore. These mouth lesions can also form when you brush too hard or from irritation caused by braces or dentures.
• Stress and fatigue: Emotional stress, anxiety, and hormonal changes can lower your immunity, causing canker sores. For instance, think of exam week at college or a stressful work deadline. These are the kinds of high-pressure moments that often bring out canker sores.
• Food triggers: Spicy, acidic foods can irritate the lining of your mouth, causing canker sores.
• Nutritional deficiencies: According to the Mayo Clinic, a lack of vitamin B-12, iron, or folate may increase the risk of getting canker sores. That’s because these nutrients keep your mouth tissues strong and healthy. When you’re low on them, your mouth will likely develop canker sores.
• Allergic reactions: Some people react to certain foods or toothpaste ingredients like sodium lauryl sulfate, causing canker sores.
• Immune system problems: Conditions like lupus, Crohn’s disease, celiac disease, or Behcet’s disease can make you more prone to canker sores.

Cold Sores

Cold sores are caused by the herpes simplex virus. Unlike canker sores, they can easily spread from one person to another. 

Once you’re infected, the virus stays in your body forever and can flare up again when triggered.

• Direct contact: Kissing, sharing utensils, or making skin-to-skin contact can spread the virus.
• Stress or fatigue: Stress and fatigue weaken your immune system, triggering cold sores.
• Sun exposure: Sun exposure may reactivate dormant HSV, triggering cold sores.
• Certain Illnesses: Illnesses or certain health conditions can weaken your immune system, making it easy to get cold sores.

Canker Sore vs Cold Sore: Differences in Appearance and Location

The main difference between a canker sore and a cold sore lies in their cause and location. Here’s how you can tell them apart.

Available Treatments and Home Remedies

Canker sores and cold sores often heal naturally over time, but the healing time varies from one person to another. Minor canker sores often go away in 1 week, while cold sores can take 2 weeks. If the pain is too severe or the sores keep recurring, then you can use certain treatments and home remedies to help fight the sores.

Home Remedies

There are simple home remedies that can help with canker sores and cold sores, but there isn’t enough evidence to prove how effective they are. Therefore, be cautious and talk to your healthcare provider if you experience any irritation while using these remedies.

Home Remedies for Canker Sores

Apple Cider Vinegar

Apple cider vinegar (ACV) is a common home remedy that you can use for canker sores. It has antibacterial properties and therefore reduces oral bacteria, speeding up the healing process. 

However, since it’s acidic, it can sometimes irritate or worsen canker sores. Therefore, use it carefully. 

How to use it:

• Mix 1 teaspoon of ACV with 1 cup of water.
• Swirl the mixture around your mouth for 30–60 seconds.
• Spit it out and then rinse your mouth well with water.
• Repeat this process once or twice a day if needed.

It’s important to note that ACV can weaken and damage tooth enamel due to its acidic nature. So, rinse your mouth thoroughly after using it.

Salt Water Rinse

Salt water is one of the simplest and most trusted home remedies for canker sores. While it can sting a little, rinsing your mouth with salt water may help dry out the sore and reduce the swelling. It’s safe, easy to make, and can be repeated throughout the day when needed.

How to use it:

• Dissolve 1 teaspoon of salt in ½ cup of warm water.
• Swirl the mixture around your mouth for 15–30 seconds and then spit it out.
• Repeat every few hours as needed.

Baking Soda  

Another easy at-home treatment for canker sores is baking soda. It works by balancing the pH in your mouth and calming irritation, which can make the sore feel less painful. Although it has a slightly salty taste, it is safe and gentle to use. 

How to use it: 

• In ½ cup of water, dissolve 1 teaspoon of baking soda. 
• Swish the solution in your mouth for 15–30 seconds and then spit it out.
• Repeat every few hours as needed.

Home Remedies for Cold Sores

Since cold sores appear on the outside of your lips or mouth and are caused by a virus, home remedies focus on managing outbreaks, easing discomfort, and preventing the sores from spreading.

Aloe Vera Gel

Aloe vera is well-known for its soothing effects. Applying a small amount of pure aloe vera gel to your cold sore can cool the area, reduce irritation, and keep it moisturized. This may also help you heal faster.

Ice or Cold Compress

You can also use an ice or cold press to ease cold sore pain. Wrap an ice cube in a cloth or use a cold washcloth, then hold it on the sore for a few minutes. This helps numb the pain and reduce swelling. However, you need to be careful not to put ice directly on your skin, as it can cause irritation or damage.

Sunscreen

Putting sunscreen on your lips can help prevent cold sores. Sunlight can sometimes trigger an outbreak, so using a lip balm with SPF 30 or higher gives your lips protection and lowers the chance of sores coming back.

Medical Treatments 

If your symptoms don’t go away, you may need to see a dentist or primary care doctor who may recommend one of the following options:

Canker Sores

Medical treatment for canker sores typically falls into these four categories:

1. Occlusive agents: These are substances that form a protective coating over the sore to shield it from irritation caused by food or temperature changes. A good example is Kank-A® Mouth Pain Liquid, which forms a protective barrier that helps soothe pain caused by mouth sores.
2. Cleaning agents: These help clean bacteria and debris from the sore. You can use mouthwashes with chlorhexidine or triclosan.
3. Local anesthetics: These numb the area to reduce pain. The local anesthetics you can use include lidocaine and benzocaine.
4. NSAIDs (nonsteroidal anti-inflammatory drugs): Your doctor may also prescribe NSAIDs such as diclofenac to help reduce inflammation and pain.

Cold Sores

Topical creams and ointments are common medical treatments used to treat cold sores: These are applied directly to the sore and work best when you start using them as soon as you feel that first tingle. These products are designed to:

• Relieve pain, burning, and itching that come with cold sores
• Soothe and cool irritated skin for quick comfort
• Keep lips moisturized to prevent cracking and dryness
• Support faster healing when used at the first sign of a tingle or sore

Blistex offers a Cold Sore Treatment Docosanol Cream 10%, recommended by dermatologists, to help manage cold sores. The FDA-approved active ingredient in this product, Docosanol 10%, penetrates the skin quickly and blocks the HSV-1 virus from entering surrounding cells. Because Blistex is available over the counter, it’s a convenient option you can start using right away when you notice symptoms. Unlike many home remedies, it’s specially formulated to provide quicker and longer-lasting relief. 

• Oral antiviral drugs: When taken early, prescription medications such as acyclovir, valacyclovir, and famciclovir are highly effective. They aid in reducing cold sore outbreaks.
• Pain relief medication: Your doctor may prescribe pain relief medication to help ease the pain and discomfort. Blistex Fast Acting Cold Sore Pain Relief helps ease pain quickly while creating a hydrating barrier to prevent cracking and speed up healing.

Prevention and When to Seek Medical Advice

Canker sores and cold sores are both painful and can make eating uncomfortable. The good news is that you can lower your chances of getting them, especially if you know what triggers them.

When to See a Doctor

Most canker sores and cold sores heal on their own, but you may need to seek medical care if:

• They are large and very painful.
• They don’t heal within 2–3 weeks.
• You keep getting outbreaks more often.
• They are very painful or make eating and drinking difficult.
• They come with fever or other symptoms.
• They appear near your eyes. 
• They look infected.
• You’re pregnant or taking other medications and unsure what’s safe.

Stop Sores Before They Start

The main difference between canker sore and cold sore lies in their cause and location. Canker sores usually form inside the mouth and can be caused by a range of factors. Cold sores, on the other hand, are caused by the herpes virus (HSV-1) and often appear on or around the lips. They are contagious and can be spread by kissing or sharing utensils with infected people.

Both types of sores can be painful and can affect the quality of your life. For cold sores, over-the-counter treatment options, like Blistex Cold Sore Treatment Docosanol Cream 10% & Blistex Cold Sore Fast-Acting Pain Relief, can help relieve pain, soothe irritation, and support healing. 

But if your sores are very painful or take longer than usual to heal, it’s best to talk to a healthcare provider. This way, you can rule out other health issues and find the right treatment.

Frequently Asked Questions

Sources:

• https://www.nm.org/healthbeat/healthy-tips/is-it-a-canker-sore-or-a-cold-sore
• https://www.healthline.com/health/canker-sore-vs-cold-sore#takeaway
• https://www.medicalnewstoday.com/articles/canker-sore-vs-cold-sore#summary
• https://www.colgate.com/en-ph/oral-health/mouth-sores-and-infections/canker-sore-vs-cold-sore-spot-these-3-differences
• https://www.goodrx.com/health-topic/oral/canker-sore-vs-cold-sore?srsltid=AfmBOoqo8hgjVLcZB6g5sk8KcQErNte9u4GBhjbg7KR97uKNbczr43Bd
• https://www.orajel.com/en/resource-center/cold-sore-pain-relief/difference-between-canker-and-cold-sores
• https://www.health.com/condition/herpes-simplex/canker-sore-vs-cold-sore-difference
• https://www.colgate.com/en-us/oral-health/mouth-sores-and-infections/canker-sore-vs-cold-sore-spot-these-3-differences