Hello. In 2006, after a lifetime of normal 120/70 range BP readings, I began to have dizzy spells and to black out when I got up suddenly, or even, sometimes, when I was just sitting still. My temperature, which used to be normal, dropped, and my heartrate was habitually slow (except in response to dizzy/black out situation, when it would speed up and beat hard in an effort to get oxygen to my brain). Silly doctor initially congratulated me for being so healthy what with the BP, and heartrate. My protests that my lifestyle didn't support that conclusion went unheeded. Finally, I saw an endocrinologist and was tested for adrenal function with an insulin tolerance test. The results revealed that I had borderline adrenal insufficiency (Addison's). The popular terminology for this is adrenal fateague. Current thinking is that the years of Lyme and coinfections taxed my system, causing this. I was treated with steroids initially - Cortef - and felt much better. I am now not taking anything but, as someone else mentioned, I do eat salt when my BP is low, and I make sure I am thoroughly hydrated at all times. The only other remaining consideration is that I am unable to respond well to physically stressful situations, so if I have a medical procedure, I need a stress dose of cortisone before and during to help maintain my BP.
If the low BP, heartrate, and body temperature are new for you, it may be a good idea to get it checked out.
I have Lyme; it doesn't have me.