Overview
Cold sores are small, painful, fluid-filled blisters around the lips and mouth caused by the herpes simplex virus, which most people catch in childhood and then carries for life. The virus stays dormant and flares now and then, often triggered by fever, sunlight, stress or illness. Outbreaks usually heal on their own within one to two weeks. Antiviral creams and tablets, started early, shorten attacks, and the virus spreads easily through kissing and shared items during a flare.
Symptoms
- Tingling, itching or burning around the lips before blisters appear
- Small fluid-filled blisters, usually on or around the lips
- Blisters that burst, weep and crust over
- Soreness and mild discomfort
- Flares triggered by fever, sun, stress or illness
When to see a doctor
See a doctor if cold sores are frequent, very painful, slow to heal, near the eyes, or if you have a weak immune system.
Causes
The herpes simplex virus, spread by direct contact — kissing, sharing utensils, lip balm or towels — most easily when blisters are present.