Health News & Info — Cold sore

Cold sores are small, painful blisters that usually form around the lips and mouth. They are caused by the herpes simplex virus (HSV), which stays dormant in the body and can reactivate at different times in life. Outbreaks are extremely common, and many people experience them more than once. While summer sunlight and UV exposure are well-known triggers, cold sores also tend to flare up in autumn and winter. Colder weather, dry air, seasonal viruses and a weakened immune system can all make it easier for HSV to reappear. Stress and tiredness during busy periods further increase the risk. Cold...