Medically reviewed by Patrick Carroll, MD
Written by Our Editorial Team
Last updated 2/24/2020
"Are canker sores herpes?" is a pretty fair question to ask if you've never experienced a herpes outbreak before. If you’ve developed a canker sore, it’s easy to assume it’s part of a larger viral infection such as HSV-1. While canker sores and cold sores have similar names and affect similar body parts, the two types of sores are completely different in nature.
In this guide, we’ll answer the question, "Are canker sores herpes?" and explain how canker sores and cold sores are different, as well as the causes of each type of oral sore.
Canker sores are small, painful ulcers that develop in the mouth. Most canker sores develop on the gums, typically near the teeth. However, they can also develop on the roof of your mouth or towards the back, near your tonsils.
Canker sores can be simple or complex. Simple canker sores tend to affect people in their teens and early twenties, although they can affect people of all ages. Simple canker sore outbreaks usually occur every three to four months and can be triggered by a variety of events.
Complex canker sores can affect people of any age. These sores usually develop in people with compromised immune systems, such as people with lupus, celiac disease, ulcerative colitis and immunodeficiencies such as HIV/AIDS.
While scientists haven’t yet discovered the precise cause of canker sores, they have been linked to viral infections or immune system problems. Several factors are thought to contribute to canker sore outbreaks:
Stress is one of the factors most closely associated with canker sores. People who are overworked or stressed are more likely to develop canker sores than people with lower levels of stress.
Tissue injury to the gums and mouth can cause canker sores to develop. Biting into a sharp object in food, cutting your gums on braces or accidentally biting your gums can also potentially trigger a canker sore.
Acidic foods, such as citrus fruits and certain juices, are also believed to increase your risk of developing a canker sore.
Vitamin and mineral deficiencies caused by poor eating habits can also contribute to the development of canker sores.
One of the most popular questions about them is: Are canker sores contagious?
Canker sores are not contagious, meaning there’s no risk of you spreading a canker sore from your mouth to your partners’ through kissing. They’re also not an STD, meaning you don’t need to be worried about spreading canker sores to a partner’s genitals through oral sex.
Treating canker sores is simple. Most sores will heal on their own in around seven to 14 days. To treat the discomfort caused by a canker sore, you can apply a topical ointment with benzocaine, lidocaine or another topical anaesthetic to your gums.
In general, while many people will experience canker sores from time to time, focusing on a healthy, low-stress lifestyle and eating a nutritious diet will reduce your risk of outbreaks.
Cold sores are sores caused by the herpes virus that can form on or around your lips. They’re caused by the HSV-1 variant of the herpes simplex virus, which is estimated to affect around two thirds of all people under the age of fifty.
Unlike canker sores, which can affect everyone, cold sores only affect people with the herpes virus. HSV-1, the form of herpes that causes oral cold sores, is highly contagious and can spread easily through direct oral contact with an infected person.
Despite the prevalence of HSV-1, many people with the virus never experience any symptoms, meaning you may have the the virus but never notice it.
This means that if you experience cold sore outbreaks, there’s a risk of you passing the HSV-1 virus on to your partner through kissing. HSV-1 can also spread via oral sex, resulting in genital herpes. It’s even possible to spread the HSV-1 virus if you don’t have any symptoms — this is called asymptomatic viral shedding.
Like canker sores, cold sore outbreaks can be triggered by certain activities. Spending too much time in the sun, getting too little sleep or other activities that reduce the strength of your immune system can all potentially trigger a cold sore outbreak.
Cold sores usually heal on their own over a period of two to three weeks. For faster healing, you can use antiviral medication such as valacyclovir during an outbreak, or apply a topical ointment containing docosanol.
There are many different types of herpes out there, but canker sores aren't one of them.
So, are canker sores cold sores? Nope. Not even close.
While canker sores and cold sores might sound similar, they’re very different. One is an oral sore caused by lack of sleep, tissue injury or immune system issues, while the other results from infection with the HSV-1 virus.
Whether you have canker sores or cold sores, there’s usually no reason to panic. The one thing both types of oral sore have in common is that they’re both easy to treat — using a topical gel or ointment for canker sores, or a safe, effective oral medication like valacyclovir for cold sores.