Caffeine is the most commonly used, naturally occurring nervous system stimulant. It's in coffee, it's in black tea, and cola drinks, and cocoa-- well as over-the-counter stimulants such as NoDoz tablets. And it's something we often use as a means of coping with stress or the chronic fatigue that often accompanies it. Drinking coffee to handle stress is like trying to quench a fire with gasoline.

A study in the American Journal of Medicine (1982) showed that caffeine raises the blood pressure. And if you really want to promote high blood pressure, smoke a cigarette while you're drinking your coffee. The effects of nicotine and caffeine mixed are even more powerful than the effects of either taken separately. After a cup of coffee and a cigarette the blood pressure can stay up for hours.I tend to encourage people to drink less and less caffeine. A lot of people are surprised and upset to find out how addicted to caffeine they are—and if you're a regular coffee drinker you may get headaches, or sick to your stomach, or depressed when you try to quit. These symptoms are the result of an actual physiological addiction; but they are very short lived and usually last only a day or two.

You may also have a psychological expectation and tell yourself, "I've got to have coffee, or I can’t wake up." But reducing or giving up your coffee habit will actually leave you with more energy, not less.