3. Herpes Simplex Virus

Herpes Simplex Virus (HSV) is a common viral infection that causes sores on the mouth or genitals. There are two types: HSV-1 usually leads to oral herpes (cold sores), while HSV-2 is more often associated with genital herpes. The virus is highly contagious and can be spread through skin-to-skin contact, even when sores aren't visible. Although there is no cure, antiviral medications can help manage outbreaks, reduce symptoms, and lower the risk of transmission. Many people with HSV might not even know they have it, as symptoms can be mild or absent.