I feel light headed from postural changes and my heart rate shoots up when I drink coffee in the morning. I don't feel faint, but have to get up slowly after lying down.
I read
this which leads me to believe that I don't have low BP or might also have something else:
Caffeine is a widely available, inexpensive food constituent with few side effects or associations with poor health outcomes [
6,
7]. It has
vasoconstrictive properties through antagonism of adenosine receptors (A1, A2A and A2B) [8] and has been shown to modestly increase BP both acutely and in the longer term in healthy individuals [
9]. Low-quality evidence indicates that caffeine is an effective treatment for postprandial hypotension, another common problem in patients with autonomic failure, potentially through inhibition of adenosine-driven splanchnic vasodilatation [
10]. This has led to the hypothesis that caffeine may be helpful for people with nOH. Indeed, caffeine has consequently been recommended as a treatment for refractory nOH in the literature and in clinical practice, although there is no consensus regarding its efficacy