What causes heat flashes?

Question

In general. I though it was a sudden increase in blood pressure. Is that one cause, or the only one? I am so confused.

Answer 1

A sudden increase in BP can cause one to feel and/or look flushed.
More likely it's a hormonal thing. If you are a woman age 40 or over, you could be having hot flashes from the uneven levels of hormones that occur in perimenopause, or from low levels of estrogen after menopause.
Or it could be a reaction to certain medications or vitamins (niacin, for example)

Answer 2

Barberry is 110% RIGHT ON and I vote the answer as a "thumbs up".