Cold sores, often caused by the herpes simplex virus, can be triggered by factors like stress, sunlight, or a weakened immune system. The virus typically spreads through direct contact, like kissing or sharing utensils with someone who has an active sore. It can be a frustrating issue, for sure. Have you experienced cold sores before, or are you concerned about possibly transmitting or catching them? I'm here to listen and help out with any questions you have!