I was having horrible hot flashes and my doctor put me on the pills - estrogen for three weeks and then switch to progesterone for one week. the first week I went off the estrogen I ended up in the ER. Doctor insisted I was having seizures. Put me on seizure meds for about a year. No improvement. Every 30 days I'd have another episode. Sound cyclical to you? Well, it was. I have a history of hormone related migraine (puberty and going off the pill to get pregnant). Turns out the idiot neurologist was WRONG - not seizures. I went for a second opinion (when he decided the only thing to do was brain surgery) and this doctor correctly identified the migraine and took me off the meds that EXACERBATED migraine.
Ultimately, my hot flashes tapered off. Then, a few years later, they returned with a vengeance. I was in a new community with a new doctor. She prescribed a compounded estrogen cream and it worked wonders. I'm still using it at age 70 and it's great.
Long story short - be sure your doctor has a complete medical history before you take the leap.
I've been very happy with my HRT for a while.