The Real Reason You Get Cold Sores

It's not a great feeling to wake up and discover that you have a cold sore, no matter how big or small. Often confused for pimples, they usually stick around for what seems like weeks and, while you may have a vague idea of how to treat them, the key is actually knowing what causes them and how to prevent them. 

"Cold sores are caused by a virus called herpes simplex virus and are passed on usually by direct contact from someone who is shedding the virus," Cheryl Jones, professor of paediatrics at The University of Sydney and Marie Bashir Institute for Infectious Diseases and Biosecurity, explained to HuffPost Australia. "For someone to effectively pass on the virus, you have to have breaking in your skin or a break in the lining in the lip or eye or genital area. The cracks can be quite small, and you may not know you have them," she continued.

While the key is avoiding contact with anyone who has the virus, once it has been transmitted for the very first time, it is likely you will experience a breakout, most commonly around your lips. And though it will eventually calm down, Dr. Marie-Louise Daly, consultant dermatologist at The Harley Street Dermatology Clinic in the UK, told ELLE that the virus will never truly leave your system, meaning you will wake up time to time with a cold sore in the exact same place. 

"Cold sores erupt when the normally dormant herpes virus is reawakened," Daly explained. They "can be activated by stress, fatigue, from lack of sleep, after an illness like a cold or flu, and from exposure to sunlight," Carl Thornfeldt, MD, a clinical dermatologist and founder of the skincare brand Epionce told Byrdie. Other factors that may reactivate the virus include environmental factors like wind. Ultimately, identifying your specific triggers is the best way to prevent a breakout.