I Was On Micardis 80 For Couple Of Years Then

I was on micardis 80 for couple of years then I had bladder op & my b p went very low so I was taken off micardis for 2 yrs. I put back on micardis 40 mg lately as my b p crept back up. But last week I fainted my b p went very low 84 over 48. My b p if fine now but my dr put me back on micardis 20 mg now. What u think thanks