Herpes is an infectious disease caused by the herpes simplex virus. It can either be manifested as cold sores in the mouth (herpes simplex 1) or as genital sores (herpes simplex 2). Herpes is highly contagious and can be life-threatening to young infants. This is why breastfeeding mothers with herpes need to be extra careful while nursing and taking care of their infants. This article contains the information on herpes and breastfeeding.