you probably have fever blisters. you do not have to do anything to get them. they can be hereditary and come out when your resistance is low, etc. You may or may not have ever had them before. But, there is a chance that your mother or father or one of your grandparents used to get them all of the time. This is why you have them. Not because you have kissed anyone with herpes or anything like that. it is a systemic thing and they show up when they take a notion. So they could be fever blisters or herpes. If they do not go away in a few weeks see your doctor. there is a new cream out for them that will help them tremendously.