About a second after waking, before I've moved, I get very fast heartbeat for maybe a minute. When I lie in on a weekend I usually wake up then go back to sleep a couple of times and it happens each time. I wonder if it is like an orthostatic intolerance (tachycardia on standing) but with waking up that puts a sudden demand on my heart. It feels similar.
Lately I have been getting very adrenalised periods for several days, like I've drunk masses of coffee, but I tried the hypoglycemic diet (meals small and often, no sugars, no refined carbs) and have brought that under control, but the tachycardia remains.
Blood tests all normal except I am slightly low blood calcium. I've also lost weight.
Anybody experienced anything similar? Or have a clue what's going on?