Do you know what the best way is of getting over the Monday morning blues? Yes you have guessed it right; a cupful of strong and steaming coffee is what that puts you in the positive frame of mind and encourages you to shake off all the sluggishness of a long weekend. Not only the Mondays, each day of the week you will remain full of vigor and energy if you start the day with a cupful of coffee. The shot you receive in the morning through the aromatic flavor of a strong Joe will help you to stay on the toes for all day long.

This stimulant quality of coffee is attributed to the presence of caffeine in the drink and caffeine is believed to hold certain psychological impacts on human brain and nervous system. As we drink a cup of coffee, the caffeine content of the drink gets circulated all over the system and through the tissues it affects the nervous, cardiovascular, respiratory and other systems. However, caffeine can not be stored in the body, so has effects that is only short-lived and transitory. As such coffee stimulates our nerves. As students we all experienced the efficacy of coffee in keeping us awake and helping to concentrate more. It is the caffeine in coffee that helps us to stay alert and fight against fatigue. Also one or two cups of coffee help us to resume the work with renewed vigor.

But this does not mean, caffeine is all good and no evil. There are certain disadvantages of caffeine consumption that may lead to adverse effects on sensitive individual. Too much caffeine may affect one's sleep pattern by delaying the onset of sleep, or reducing sleep time. With consistent caffeine consumption, the subjective quality of the sleep may also fall. Caffeine also works for mood swing in some person. While it is commonly associated with pleasant stimulation for some it may lead to anxiety, nervousness and irritability. But these adverse effects are only the result of excessive consumption of caffeine and if you are a moderate coffee drinker, you do not have to bother about this.

Now let's discuss about the physiological effects of caffeine. Its short term effect includes increases in blood pressure, plasma catecholamines, plasma renin and serum free fatty acid. Drink two or more cups of coffee and you will experience an increased need for visiting the toilet. This is because, caffeine also increases the production of urine. Along with that the production of gastric acid is also increased. However, for the avid coffee drinkers, the system develops a tolerance to caffeine and the system becomes immune to its adverse effects.

How much caffeine a cupful of coffee contains does not depend on the size of the cup. The amount of caffeine in the cup mainly depends on the origin and chemical composition of the blend. The method of brewing and the strength of the brew are also the important determinant for the caffeine content in coffee. You may find less caffeine in instant or soluble coffee. On the other hand, the roasted and ground coffee contains caffeine in greater volume. If you are fond of Robusta coffee, that means you are consuming caffeine that is almost twice than Arabicas. Also take notice of the cup size. The standard coffee cup in the USA is commonly understood to contain 150 ml coffee, whereas an espresso cup contains an amount as small as 40 ml.

According to U.S. Food and Drug Administration, the upper level of caffeine may vary with the types of coffee depending on whether it is roasted, whether brewed by drip method or percolated and so on. Generally it should not exceed 120 mg for a 5 oz cup for instant coffee and for roasted and ground coffee the upper limit has been fixed at 170 mg for the same amount of drink. In case you are going for decaffeinated coffee, a cup should not contain more than 3mg caffeine.

Finally, it has been established by scientific researches that if you are a moderate coffee drinker, you do not run any risk of developing cardiovascular or other chronic diseases. However, those who have symptoms of irregular heartbeats may go for decaffeinated coffee.