What are cold sores?
Cold sores, also known as fever blisters are small fluid-filled blisters that develop on or around the lips. They are caused by the herpes simplex virus (HSV-1), which is transmitted by direct contact. Eventually, the blisters erupt, scab over and finally heal. After an initial outbreak, the virus remains dormant in the nerve cells near the site of infection. Periodically, the virus can reactivate and cause new outbreaks. The frequency of these outbreaks can vary from person to person and can be influenced by a number of factors such as stress, illness, or hormonal changes.