Understanding What Causes Cold Sores: Transmission, Symptoms, and Treatment

Cold sores can pop up without warning, and if you've never had one before, it may worry you to see the blister form on your lip. However, cold sores are more common than you may think. According to the National Institutes of Health, over half of Americans contract the virus that causes cold sores by the time they reach their late 20s.

Here's what you need to know about the unsightly -- but manageable -- red bumps that may form on your mouth.

What Causes Cold Sores?

Cold sores are caused by a contagious virus called herpes simplex 1. Although the virus is related to herpes simplex 2, which causes genital herpes, it's not the same thing. Once contracted, the virus is incurable, but it generally stays dormant in the body. The disease can reactivate at any time, but the American Academy of Dermatology (AAD) notes that trauma, hormonal changes, stress, sun exposure, or a weakened immune system can all increase your chances of having a breakout.

It's important to note that cold sores and canker sores are not the same thing. The causes of cold sores are understood, while the origin of canker sores is generally unknown. Both share similar triggers and appearances, but canker sores are more commonly found inside the mouth and are not contagious.

Transmission of Cold Sores

To understand what causes cold sores, it's important to know how the virus is contracted. It spreads through direct contact with someone who has active lesions. The AAD explains that the virus spreads when people kiss, touch, or share food, beverages, skin care tools, or cosmetics. It's also possible to contract cold sores through oral sex.

Signs and Symptoms

According to the World Health Organization, an itchy, tickling, tingling, or burning sensation on the lips or face is an early indicator that a cold sore is forming. You may also experience aching muscles, a mild fever, or swollen lymph nodes. A cold sore may follow these symptoms, and you might develop more than one sore.

Treatment and Prevention

The virus that causes cold sores is incurable, but the U.S. Centers for Disease Control and Prevention explain that the symptoms are controllable though the use of antiviral creams such as Abreva or Denavir. These creams are most effective if applied frequently during the early stages of an outbreak. You can also talk to your doctor about using antiviral medications such as Valtrex and Zovirax. Furthermore, some people find that lip balms and cold compresses help with the pain of active cold sores.

While cold sores are manageable, they are not just harmless blemishes, especially among children and people with HIV or certain cancers. One prominent danger is that the virus can cause a serious eye infection. If you have cold sores, it is important to wash your hands frequently and keep them away from your face. You should also avoid peeling off the scabs that form on your sores.

While extremely common, the herpes simplex 1 virus is still misunderstood by many people. The bottom line is that cold sores are not the same as genital herpes and are a manageable condition. However, if you may have been exposed to the herpes simplex 2 virus, you should ask your health care provider to test for sexually transmitted infections.