Can a person's cold sores lead to genital herpes?

Yes: Cold sores are caused by herpes simplex virus type 1. Genital herpes is usually caused byhsv type 2. However, type 1 can be passed from a cold sore to the genital area through oral- genital sex. Type 1 genital infections are usually less severe than type 2 but are treated the same way.

On who?: If you have it on your face it cannot spread to another area. You could give it to another person but only if that person does not have the virus already. Most people already have hsv1 cold sore virus without symptoms but will reveal immune antibodies on a blood test.