Do cold sores usually hurt?

Yes. Cold sites hurt due to the damage caused by the viral outbreak. The initial tingly stage, called a prodrome, progresses to a vesicular, or blistering, outbreak which is quite painful. Once the vesicles burst, the lesion scabs and generally is no longer painful. Total time 7-14 days.
Can. Cold sores usually are sore due to open sores that expose tissue that is usually protected, your bodies defense ability moves in to cause some swelling that can hurt due to increased pressure on the nerves in that area, and eating can also irritate with hot or cold setting it off.