Hi, my husband has hepatitis c and he has never had a migraine headache. I don't know if there is any relation to the two. If your friend is stressed out about it, which he probably is if he just found out, maybe that is causing the migraines.
My husband had a liver biopsy last june and his doctor just mailed him a yearly checkup reminder card. So i'm guessing it's good to get your blood counts checked at least once or twice a year. Some people get checked more frequently.