It is a lifelong disease with no cure. There are two viruses that can cause herpes and these are the HSV type 1 and HSV type 2. The blisters can be caused by any of these viruses. While HSV type 1 virus affects the affects the mouth and HSV type 2 affects the genital regions. HSV enters the body through a mucous membrane or a small opening in the skin due to direct contact such as kissing, touching etc. It can also transfer through saliva or by skin contact with people who have no visible sores or other symptoms. After the infection the virus gets dormant within the body and aggravates during stress etc and giving rise to blisters.
The primary affect of both the types of herpes causes painful blisters. Symptoms of an initial herpes outbreak generally occur within two weeks after infection, and are usually more severe than subsequent recurrences. The blisters may also be accompanied by fever, swollen lymph nodes, and oral herpes sores within the mouth or throat may occur. In genital herpes there are outbursts of general blisters which are preceded by a painful tingling sensation known as prodrome. These blisters appear within a few days .These blisters can even develop into open, crusty lesions which are very painful and last for two to three weeks.
One should refrain from popping herpes blisters as it is a tendency since many people think the blisters are pimple when the first blisters appear. You are risking further infection. Blisters pop themselves and will look like sores, but will crust up to disappear with time.