Cold sores, also called fever blisters, are small, fluid-filled lesions typically appearing on or around the lips. They’re caused by the herpes simplex virus type 1 (HSV-1), which affects nearly 67% of people under age 50—often without them even knowing. The virus can stay dormant in the body and reactivate due to various triggers.

Common triggers include stress, illness, hormonal changes, sun exposure, or even a weakened immune system. Most people notice a tingling or itching sensation before a cold sore appears. These blisters can be painful but usually heal within 7 to 10 days without leaving scars.

While there is no cure for HSV-1, antiviral medications like acyclovir and valacyclovir can shorten outbreaks and reduce their severity. Over-the-counter creams like docosanol may also ease symptoms. Some people find relief with natural remedies like aloe vera or cold compresses.

To reduce outbreaks and prevent spreading the virus, avoid kissing or sharing personal items during a flare-up, apply SPF lip balm, and manage stress levels. Remember, HSV-1 can be contagious even without visible sores—so staying informed is key to managing this common condition effectively.