wild swings in blood pressure

[dyade]

Two nights ago, my wife, (50 yrs old, average weight, very healty) had blood pressure readings around 180/105.  She woke up with a very bad headache, but we don't know if it is related.  Went to doctor first thing in the morning; readings were 170/100.  He perscribed Lisinopril-HCTZ 20 / 12.5mg tablets.  We purchased a home blood pressure monitor, our readings were similar to doctors 2 hours later, at 165/105.  Blood pressure dropped very quickly since then, 125/85 last night, and 115/78 this morning.  

Is this normal?  I have a hard time believing the medication acted this quickly.  It seems more like a one-off event, (i.e. some other cause for high blood pressure). Should we be concerned, or should we be looking at other causes of this very very high blood pressure reading?

Thank-you very much -
Concerned Husband.

Other information:  This is the first time she has noticed excessively high blood pressure.  Last BP reading was 6 weeks ago, blood pressure was around 130/85.  Her blood pressure has always been normal or slightly high, as it was 6 weeks ago.   There is some history of high blood pressure in her family.

[Cleveland Clinic]

Because of her age (relatively young) she should have work up for secondary causes of HTN.  Especially, she should have a renal ultrasound to rule of renal artery dysplasia.  There are also a bunch of blood and urine test that should be performed.  

[bigkev414]

this happens to me occasionally. I wake up in the night and feel very 'shaky' and flushed. my heart rate is up a bit also and I feel giddy and kind of tremble inside. i also have a home monitor and my BP when I have these 'turns' has gone as high as 220/118. I have gone to the ER with this, and they are puzzled. Tests all came back OK, and the doctor says they are not concerned if this happens occasionally, and then goes back down again. I have a history of SVT's (rapid heart rate) but control it well with Atenalol, which is also for BP. I have a theory about this and it's related to food and digestion. Sometimes I can't sleep at all, and get shaky etc and it depends what I eat. In the ER they gave me a big dose of Antacid medication when i went in with the high BP, and wouldn't commit themselves as to why. It helped. I'm not a food crank or anything but am absolutely convinced that some food additives and the chemicals used in fertilizers and animal feed react on my central nervous system. My advice is to try taking some antacid if it happens again and see what happens, and I occasionally take a low dose of Valium to keep me calm. It works well. Don't take your BP too often because it can drive you mad ...it fluctuates widely during the day. Don't worry - they tell me this happens to lots of people and they don't know why, and it doesn't seem to do any damage. Anybody else have any ideas?