They are horrendous, aren't they? Migraines are hereditary - my mother gets them, I do and both of my children do. You have to learn what your triggers are and learn to avoid them. I haven't had a migraine in a long time as a result. The worst one I ever had lasted 2 months, and I was off work, subjected to daily tests at the hospital, brain scans, dye being ejected everywhere, a spinal tap, and so on. For me, the warning signal is the light show - if I can get some Tylenol into me within 5 to 10 minutes of the light show starting, I can usually deflect the migraine! Usually being the operative word - not always!
I carry Imitrex with me for them, but haven't had to use it in years. If they last several days, sometimes a shot of demerol at the doctor's office or hospital will help. But not always. The best way to combat them is to find out what your triggers are! For me it's flashing lights, whether through moving blinds, traffic lights, a ceiling fan with lights that is on, or a severe change in the atmospheric pressure.
Migraines are terrible to deal with, and those that have never had one cannot even imagine the pain that you go through. Noise, light, even moving your head causes unbelievable pain. I think childbirth was easier.
I find that if you are seeking medical help for them, it helps if you track them on a calendar - write down start time and end time on each date. That gives the physician an idea of the severity and frequency of attacks and makes them more amenable to helping you.