Cold sores are typically caused by the Herpes Simplex Virus Type 1 (HSV1), and once a person is infected, the virus continues to live in the body and causes occasional attacks. When the body’s immune system is weakened, cold sore outbreaks can occur for up to two weeks. Thankfully, there are a variety of treatments available to deal with cold sore outbreaks, like antiviral prescription medications (usually topical medications that are applied to the site of the outbreak). Another great option is a simple, pain-free laser treatment, which can speed up healing and reduce pain/inflammation in about 48 hours and in some cases reduce the recurrence rate and size.