It is expected to be an evolutionary process, meaning it will develop and expand as time passes, getting better as time goes on. Service A study by researchers at the Oklahoma City VA Medical Center suggests that caffeine can push blood pressure to unhealthy levels when taken in stressful situations. Their study findings were recently published in the American Journal of Hypertension. Caffeine alone sent blood pressure up in all 31 male medical students that they tested. Students who already had high blood pressure, or a family history of high blood pressure, had the highest spikes in blood pressure with caffeine, the researchers found.
Caffeine also raises levels of cortisol, a hormone released during stress.
People often turn to caffeinated beverages when they are stressed, which might be precisely the wrong thing to do, according to other studies. Moreover, long-term coffee drinkers often believe that they have become immune to the effects of caffeine, but studies show this is not the case. One study found that a single dose of caffeine elevated blood pressure for as long as 12 hours. Given the cumulative effects of stress and caffeine, the researchers concluded that it might be beneficial for people at high risk for hypertension to refrain from routine use of caffeinated beverages, particularly when work demands and related stressors are at high levels. Nearly 50 million Americans are estimated to have high blood pressure, which often causes heart disease, strokes and kidney failure.