Cold sores, also known as fever blisters, are a common viral infection most often caused by the herpes simplex virus type 1 (HSV-1). HSV-2, typically linked to genital herpes, can also cause them through oral–genital contact.
These tiny blisters are highly contagious. They can spread through a simple kiss, sharing items like utensils, towels, or lip balm—or even by touching the sore and then another part of your body.
An outbreak usually follows a telltale pattern:
- Tingling or itching a day or two before a sore appears
- Blisters forming around the lips
- Painful rupture of the blisters
- Scabbing and healing within 7–10 days
But the virus doesn’t truly go away—it hides in your body, ready to reactivate when triggered by stress, sun exposure, hormonal changes, illness, or a weakened immune system.
While there’s no cure, antiviral medications like acyclovir or valacyclovir can shorten outbreaks. Topical creams, pain relievers, and moisturizing balms help manage discomfort. Prevention is key: avoid close contact during outbreaks, don’t share personal items, use SPF lip balm, and keep your immune system strong.
Why this matters even more than you think:
Recent research has uncovered a surprising connection between oral health and Alzheimer’s disease. Scientists have found toxic enzymes from gum disease bacteria (P. gingivalis) in the brains of Alzheimer’s patients—even in people who hadn’t yet shown dementia symptoms. This suggests the infection could play a role before memory loss begins.
In mouse studies, a compound called COR388 reduced harmful protein buildup and brain inflammation. While human treatments are still on the horizon, researchers stress that protecting your oral health may be more important than ever—especially since no new dementia drugs have emerged in over 15 years.