Cold sores, also known as fever blisters, are a common sign of infection with the herpes simplex virus type 1 (HSV-1). As the article warns, “If it comes out in your mouth, you are infected.” The virus spreads easily through kissing, sharing utensils, or touching an infected area and then another part of your body.

Early symptoms often start with tingling or itching around the lips, followed by small fluid-filled blisters. “Blisters rupture, forming painful red sores,” which is the most contagious stage. The sores usually heal within 7–10 days, but the virus remains in the body and can return.

Recurrences are often triggered by stress, sun exposure, hormonal changes, illness, or weak immunity. Antiviral treatments like acyclovir or valacyclovir can shorten outbreaks, and soothing creams or pain relievers can ease discomfort. Experts advise avoiding close contact during outbreaks and not sharing personal items.

The article also mentions a possible link between oral bacteria and Alzheimer’s disease, citing research that found “gingipain antigens in the brains of Alzheimer’s patients.” This raises the question of whether infections from the mouth could contribute to brain diseases.