If you're a person who gets the occasional cold sore, you've probably heard about a virus called herpes simplex. Herpes simplex virus, or HSV, is the cause of those painful sores around your mouth. HSV belongs to a family of viruses called herpes viruses. This ill-favored family also includes viruses which cause mono, chicken pox and shingles. Even though they share a family, having one of these viruses doesn't mean you'll get the others. This is ALSO true for the herpes simplex virus, which comes in TWO variants, called herpes simplex one and two. Generally, cold sores are attributed to the first type, HSV-1, while their below-the-belt equivalent, genital herpes, is attributed to HSV-2. But, either type one OR type two can occur in the oral or the genital area. Still, HSV-1 is the culprit behind some 50-80-percent of cold sore casualties ...so how does it work? Once you're exposed to HSV for the first time, the virus enters your body, replicates itself, and spreads. For some, this leads to their first ever cold sore, often accompanied by fever, sore throat, and swollen lymph nodes. For others, these initial symptoms are so minor they'll go undetected. But no matter the severity, the body looks on HSV as an invader and sends immune system forces to attack it. HSV-1 responds by retreating along nerve pathways and hunkering down in a group of nerves at the top of the spine called the ganglion. Once there, the virus "goes to sleep," or enters what is known as latency. Unfortunately though, HSV wakes up--no one is 100 percent sure why--and it'll live in the body forever. When it wakes, it travels up the nerve pathways and back to the site of original infection. This usually results in a new herpes outbreak, and that's why most people who have one cold sore will eventually have another. But SOMETIMES, the awakened herpes simplex virus won't cause symptoms. This is known as asymptomatic shedding. The bad news is that an unknowing person experiencing asymptomatic shedding is still extremely contagious. This is part of the reason that HSV-1 is so common! In fact, various studies estimate it infects 50 to 98-percent of the population, although many are asymptomatic. So if you've got HSV-1, you're definitely not alone...but you might want to learn more about the virus and its effects on your body! For information ranging from treating cold sores to kissing someone with them, watch other videos in this series.