Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.
The cause of fever blisters is a strain of the herpes simplex virus. The virus is highly contagious and affects up to 80 percent of children and adults in the United States, according to the National Institute of Dental and Craniofacial Research. Other common names for fever blisters are oral herpes and cold sores.
