Many people don’t know the truth about what causes cold sores (aka “fever blisters”).
In this article, I’m going to explain in detail what causes cold sores, and why people keep getting cold sores.
First of all, I want you to know that I suffered from cold sore outbreaks for about 20 years of my life.
And for a few years, I would get a cold sore on average every 2-3 months.
It was no fun.
The humiliation and loss of self-esteem were totally crushing. During outbreaks, I suffered from depression and anxiety, and I would avoid contact with people as much as I could.
What Causes Cold Sores?
I’ll never forget the day I learned what causes cold sores. I had a cold sore blister on my lip, with some medicinal ointment on it, and my friend looked at me and said “ooh gross! You have herpes!”
How did I respond? “No man, it’s just a cold sore!”
What I didn’t realize at the time, was that my cold sore outbreaks were in fact caused by herpes simplex virus (HSV).
Yes, I said it…herpes.
Imagine my shock when I learned that I had herpes labialis. In medical terms, “labia” is a general term for “lip.”
“Great!!! I have lip herpes!” I thought to myself (with sarcasm).
The Herpes Simplex Virus
When I got home, I went to my computer to do some research. I found out that my friend was right…cold sores are caused by a type of herpes virus.
There are two types of herpes simplex virus, and both can cause cold sores.
HSV-1 typically is responsible for cold sores, and HSV-2 is most often the cause of genital herpes.
However, both types of HSV can cause cold sores or genital herpes (e.g. from oral sex).
After primary infection, the virus resides in the associated dorsal root ganglion where it lies dormant until an external stimuli (such as stress or immunosuppression) initiate reactivation of the virus from dormancy.
Unfortunately, the virus lives on forever, and that’s why people continue to get cold sores over and over again.
There is no cure…only methods for prevention and treatment.
Why Do I Keep Getting Cold Sores?
Many people that visit my website as the question: “Why do I keep getting cold sores?”
To provide an answer to this question, I’m going to quote a passage from an awesome Virology Blog:
Herpes simplex viruses are associated with latent infections, a type of persistent viral infection that lasts for the life of the host. Infection with herpes simplex virus begins with intimate contact with an individual who is shedding the virus.
Virions enter the oral or genital mucosal tissue and replicate, perhaps producing one or more lesions. While the infection runs it course and the lesion disappears, the virus makes its way into sensory nerve endings and finds a permanent home in neurons.
There the viral DNA remains silent until an insult – stress, ultraviolet light, hormonal changes – triggers viral replication. New virions are made, which travel to the epithelial surface, resulting in a lesion. Shed virus may be transmitted to others. The lesion heals and viral replication ceases until the next insult.”
In basic terms, there is an initial infection with the virus, then the virus makes a home and moves into your nerve endings, where it lies dormant until you have a weakened immune system, sunburn, stress, or some other factor that results in viral activation, replication, and finally…cold sore outbreak.
What Causes Cold Sores? – Cold Sore Triggers
Now you know that the herpes simplex virus is what causes cold sores, and you also know why you keep getting cold sores…because the virus lives in nerve endings forever, and there is no cure, only prevention and treatment.
According to HopkinsMedicine.org, 50 percent to 80 percent of U.S. adults have herpes simplex virus.
However, not everyone suffers from cold sore outbreaks.
The lucky ones with oral herpes never have a cold sore outbreak. For the unlucky ones, they suffer from cold sores on a regular or semi-regular basis.
Although the specific triggers that cause cold sores to recur are unclear, several factors may play a role.
Some factors are:
- A recent fever
- Emotional stress
- Immunosuppression
- Physical injury
- Surgery
- Dental work
- Menstruation
- Hormonal changes
- Sunburn
- Anger
- Anxiety
- Certain foods (e.g. nuts, seeds, chocolate)
Cold Sore Symptoms
The following information on cold sore symptoms was taken from MayoClinic.org.
A cold sore usually passes through several stages:
- Tingling and itching – Many people feel an itching, burning or tingling sensation around their lips for a day or so before a small, hard, painful spot appears and blisters erupt.
- Blisters – Small fluid-filled blisters typically break out along the border where the outside edge of the lips meets the skin of the face. Cold sores can also occur around the nose or on the cheeks.
- Oozing and crusting – The small blisters may merge and then burst, leaving shallow open sores that will ooze fluid and then crust over.
Signs and symptoms vary, depending on whether this is your first outbreak or a recurrence. They can last several days, and the blisters can take two to four weeks to heal completely. Recurrences typically appear at the same spot each time and tend to be less severe than the first outbreak.
During first-time outbreaks, some people also experience:
- Fever
- Painful eroded gums
- Swollen lymph nodes
- A headache
- Muscle aches
- A sore throat
Children under 5 years old may have cold sores inside their mouths and the lesions are commonly mistaken for canker sores. Canker sores involve only the mucous membrane and aren’t caused by the herpes simplex virus.
Cold Sore Treatment
Over the span of 20 years, I tried many things for treating my cold sores. Some worked alright, and some were nothing short of a miracle.
Here are common cold sore treatments:
What Causes Cold Sores? – Conclusion
To sum things up, let us review these key concepts:
- Cold sores/fever blisters are tiny blisters that develop on the lips or around the mouth.
- Cold sores are caused by the herpes simplex virus (HSV).
- Cold sores typically last from 7-10 days untreated.
- After initial infection with the virus, it lies dormant in the nerve endings, where it stays for life.
- The virus can be activated by triggers such as fatigue, injury to the affected area, and in women – their period.
- Studies suggest that about 80-90% of people in the US have been exposed to HSV-1, and about 30% have been exposed to HSV-2.
- There is no cure for cold sores, but you can do things to prevent and treat them.
- The virus is highly-contagious and is typically passed on to kids under the age of 10 from their parents kissing them.
The key to cold sores is to prevent them from forming in the first place.
Thus, I encourage you to check out my Ultimate Guide to Preventing Cold Sores.
It’s free and has absolutely everything you need to know.
If you have any questions about what causes cold sores, please post them in the comment box below.
Nancy Pipitone says
I get one about every 2 yrs last 12 days this home I did have a fever 5 days before I learn to deal with it I use alcohol
Matt says
Hi Nancy,
Thanks for sharing about this. I’ve used alcohol to deal with cold sores before as well. Glad to hear you only get cold sores every 2 years and I hope that you can start to reduce their frequency or even eliminate them completely.