Causes of Fever Blisters

Fever blisters are primarily caused by the herpes simplex virus (HSV), specifically HSV-1. This virus is highly contagious and can be easily transmitted through direct contact with an infected individual or through contact with items contaminated by the virus, such as utensils or towels. Factors such as stress, fatigue, and a weakened immune system can trigger the reactivation of the virus, leading to the development of fever blisters.