What Causes Cold Sores?

What Causes Cold Sores?

The herpes simplex virus is the main cause of cold sores. There are two types of herpes simplex virus, but the main culprit for these fever blisters is Type 1. This type affects the body tissues that are found above the waistline.

Most viral infections are caused by exposure to the germs themselves, but this is not one of the causes of a cold sore. It occurs, not with the recent contact with the herpes simplex virus, but with the reactivation of the HSV (Herpes Simplex Virus) particles that are already in your body. These germs are already residing inside the body before being reactivated, but are then “awaken.”

Initial contact with the virus does not result in the formation of cold sores; and therefore it cannot be detected at once.

A person with cold sores would first be inflicted with fever, headache, and difficulty swallowing. The person might also be easily irritable. A day or two after these initial symptoms occur, the person will feel pain in his mouth, and the gums will be inflamed. On the third day blisters appear near the mouth or lips. The blisters will pop, over time, but the person’s mouth will remain painful it will be hard to eat.

The core sores themselves will heal over time. The infection period is between 10 to 14 days. But when the virus remains in the body, cold sores can repeat again at a later date.

Most cases of such an infection occur before the age of seven. This is why many people don’t know the causes of cold sores. Further, the majority of people who are inflicted with fever blisters (another word for cold sores) don’t even know they have them. The symptoms are subclinical, and not obvious to the normal person. The patient might only feel one or two mild sores near his mouth.

Fever usually accompanies cold sores, and the common flu virus can also reactivate the cold sore virus. Getting your skin sunburned might also trigger cold sores.

What are Cold Sores?

Cold sores are lesions on the lips or on the skin near the mouth. People can be exposed to different causes of cold sores, each and every day. They are often referred to as “fever blisters.” These lesions can be painful, and usually last for a few days. They are caused by a virus. But, unlike other viral infections, cold sores are not completely eliminated by our body’s defense system. This is the reason why they usually recur over time.

Treatments for Cold Sores

What do you do when you have cold sores? How do you treat them?

There are several basic forms of treatment that have been used in the past:

  • Lysine – An amino acid taken internally.
  • Zinc – Applied directly onto the cold sores, taken internally, or both.
  • Calcium – Taken internally to help keep the system alkaline, since many people suffering from cold sores are said to have too much acidity in their systems.
  • Ice – An old-fashioned external treatment used when one feels a cold sore coming. But using ice after the cold sore has appeared may slow the healing process.
  • Tea – Applied frozen before the cold sores burst, or warm afterwards.

More Information on Cold Sores Treatments

For a more thorough description of these treatments, please see our post on Cold Sores Treatment.

Disclaimer:  These statements have not been evaluated by the Food & Drug Administration.  Nothing in this article or on this website constitutes medical advice – please consult your doctor if you are ill.

By | 2014-11-10T15:49:24-08:00 April 9th, 2009|Natural Remedies, Skin Care|

About the Author:

Megan helps others understand how they can use green technologies and tecniques to live cleaner and healthier lives, utilize natural resources, and adopt environmentally friendly living standards.


  1. Xochitl April 10, 2012 at 12:19 pm

    Hello my name Is Xochitl and my boyfriend has 3 cold sores on his lips and he told me he got the cold sore from not drinking water can you get cold sores from not drinking water

  2. lana November 1, 2011 at 4:48 am

    whooooooooo weeeeeeeeeeeee 🙂 i’m so happy

    i tried the savlon and within 2 hours it started drying up.
    i tried the salt method, alcohol pads and even strong ointment, but that didnt work.
    i was going to do the bleach method but found savlon in my 1st aid kit.
    now the skin is peeling and the sore is healing.

  3. Ollie September 26, 2011 at 3:23 pm

    I have never tried the advertised medication “cold sore free forever”, but since the cold sore is caused by a dormant virus, it stands to reason that the medication researched by a physician would not work. Viruses stay in the human body forever and may or may not lay dormant. For a doctor to claim their medication would leave someone cold sore free forever is just wrong. He/she should know this as a physician.

  4. Megan Barlow March 24, 2011 at 7:51 pm

    @Samantha – Thank you for that tip! That is very good to know, I hope it will come in useful for someone looking for answers to the problem.

  5. samantha March 6, 2011 at 10:50 pm

    I have been getting cold sores for years and i found about 2months ago that if u cont. to put white vinegar on it rite away it stops it from blistering and if it blisters b 4 u have a chance to put vinegar on it, put vinegar on blisters and it heals in 3 days!

  6. Lorena Martinez January 11, 2011 at 4:46 pm

    I like many others deal with cold sores very frecuently since a small child. This article helped me understand what causes them. Its also good to know I’m not the only one suffering from them.

    Thanks for the info :]

  7. Jasmine July 19, 2010 at 4:21 pm

    We use Lysine pills as soon as we feel a coldsore come on, it usually starts to tingle on the lips. These natural pills helps heal it quickly and has reduced the amount of cold sores we have had in the last few years.

    Thanks hope this helps.

    • Anna August 25, 2010 at 8:36 pm

      @Jasmine – Thanks for the first-hand advice!

  8. Alfons January 29, 2010 at 6:12 am

    Dear Anna,

    Thanks for sharing your insights on Cold Sores. Cold sores can be very unsightly and embarrassing to those who have them.

    I’m not a sufferer of this, [ I have other issues :o) ] but I know enough people who do. Through my wife I learned that an unbearable amount of stress, be it through work, family pressures, or illness, trigger the dormant viruses into activity.

    Stress reduction exercises, activities as simple as brisk and mindless walking (I had to add the mindless part, ’cause worrying while walking will maintain the mental stress level) help in keeping down the flare-ups.

    Of course, the presence of a loving and understanding partner helps too.

    Thanks again, Anna. Glad I came across your article. Seems like you put a lot of work into getting this piece together!

    Good job!

    .-= Alfons´s last blog ..

    • Anna August 25, 2010 at 8:56 pm

      @Alfons – You are right, taking a walk is one of the best and simplest cures there is. And yes, without too much thinking either. Stress is definitely a factor in issues and the mind affects the body more than many people would admit.

  9. Kevin April 28, 2009 at 12:30 pm

    Great article, I have just written one on the same subject, but not as comprehensive as this one. Keep it up!

  10. Monica Flora butter April 15, 2009 at 2:59 am

    Like many people I suffered the embarrassment of large open sores.I have tried patches [ seemed to make matters worse by spreading to other parts of the mouth ] and various creams all seem to help but did not clear up the problem.
    My solution SAVLON I have found it rapidly clears and cleans the wound sometimes stopping it in its tracks and not developing any scab or sores, its purpose is to heal skin and I have found it works for me. I have not tried any similar products like germolene etc. so I can not comment on these products but as each persons skin will react differently its worth trying the various options. I can only restate my experience of almost immediate healing by using SAVLON.
    I started using it with a cream to heal the skin then using it instead of the creams.If you suffer badly then give it a try it might work for you.
    I hope this helps you it is not an endorsement of SAVLON merely an honest desire to share a solution that works for me.

    • Anna April 23, 2009 at 6:55 pm

      Hi – thanks for sharing this information with other blog readers. Its always great to have some feedback from someone who has experience dealing with a particular problem.

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