11 Surprising Facts About Cold Sores

The biggest surprise? Most people already have the virus that causes cold sores. "About 2/3 of the world’s population has cold sores, or a strand of herpes called HSV-1," says Faisal Tawwab MD over email. As far as HSV-2 goes, a large number of people have that as well: 1 in 6, according to the Center For Disease Control (CDC).

Although many people do have the virus, not everyone gets it from sexual contact or kissing. "Most individuals are who contract herpes are first exposed to it as a child," says Dr. David Kulbersh, MD, Medical Director of STDcheck.com, over email. "Think of all the sharing (and oversharing) tendencies children have — sharing drinks, eating utensils, slobbery kisses for everyone, etc."

It might come as a shock that so many people have the virus, but of those who have it, many don't realize it. "You would therefore be surprised to know that many who are infected don’t know they have it," says Tawwab. "Part of it is because symptoms, such as the sores themselves, don’t show up regularly. This makes tracking a 'breakout' difficult, if not impossible. This means that transferring an infection onto a partner is more likely because you can do so without showcasing an outbreak."

Coldsores aren't exclusive to just the lip region. "Although many cold sores are found at the region of the lip known as the vermilion border, they can also pop up at other locations such as around the nose and even on the tongue," says Nesochi Okeke-Igbokwe, M.D., M.S. over email. "The infection may potentially spread to the eyes if proper hygiene practices are not maintained when one has an active cold sore."

"Changes in weather, such as sun or wind exposure, may trigger the recurrence of a cold sore," says Okeke-Igbokwe. Abrupt changes in weather trigger your body's immune system, which increases your risk of developing a cold sore (if you already have the virus, of course).

HSV-1 is the referred to as the oral strain of herpes and HSV-2 as genital herpes, but cold sores in any location can be caused by either of the strains. "This means that if an individual with an active herpes infection around the mouth area performs oral sex on their partner, they can transfer whichever strain of herpes they have to their partner’s genitals, causing a case of herpes in the genital area," says Kulbersh. "Alternatively, if an individual has either strain of the herpes virus in the genital region, and their partner performs oral sex on them, their partner could get herpes orally caused by whichever strain their partner has genitally."

HSV lesions are most contagious when they are active, but the virus can still be transmitted without a visible sore. "Low levels of the virus can still be shed during inactive periods, meaning, you can still transmit the herpes virus to someone even when you don’t have an active cold sore," says dermatologist Tsippora Shainhouse over email.

"Many people have a prodrome period immediately before the sore develops," says Shainhouse. "You can feel pain, itching, or tingling up to 1 day prior to the sore developing. It is associated with viral replication and nerve irritation. This is the time to treat with oral medications to prevent the sore from developing. If you can catch it early, you can hopefully prevent the blisters, or at least reduce the severity and duration of the episode."

The first episode of a cold sore, called "Primary herpes gingivostomatitis," is usually the worst. "It's the most aggressive looking, the longest lasting, the most painful, and possibly the one that — due to discomfort — can interfere with eating," says dermatologist Robin Evans, MD over email. "This type of episode is more typically seen in childhood."

Although there is no cure for HSV — it will remain in your body forever — that doesn't mean you have to suffer constant cold sore outbreaks. "There are prescription pills which can not only shorten the course of an active coldsore outbreak, but can prevent an outbreak from occurring in the first place," says Evans. "Treatment can be prescribed by your dermatologist."

"It is ironic that while so many people carry herpes, it has become a stigma..." says Tawaab. Many people get judged for not only their...appearance, but also for seeming 'unsafe,' 'reckless,' or 'slutty.' Because herpes isn’t yet curable, it’s something someone has to deal with," says Tawaab. "Making facts about herpes more known, more commonplace, and less of a taboo subject matter can help deter some of the unnecessary aggravations that come with the territory."