 can be caused by a lot of different things. Too much caffeine, too much alcohol. Some people will say any alcohol. Too many carbohydrates, especially the empty carbs and sugar. And these substances overstimulate the body, especially the adrenal glands. And once the adrenal glands overreact, it constricts the blood vessels, raises blood pressure, just as if you were running from or facing danger, the flight or fight issue.