Caffeine is a naturally occurring stimulant found in certain plants. It acts on the brain and nervous system. Small doses may make you feel more awake and focused, but higher amounts can make you feel anxious and jittery. Your heart rate will increase and you may have difficulty sleeping.
Coffee, tea, cocoa, cola soft drinks and certain “energy” drinks contain caffeine. Energy drinks can contain much more caffeine than you might expect, as they often also contain guarana. Many people do not know that guarana also contains caffeine, so an energy drink can contain up to twice the amount of caffeine of a cup of coffee. These drinks are not suitable for children or pregnant women.
Caffeine is also a diuretic, which means that it makes you go to the toilet more often. This can lead to dehydration. Like other drugs, it’s possible to become dependant on caffeine. Withdrawal symptoms include tiredness, irritability and headaches. You can also build up a tolerance to caffeine, which means that you require more and more to have the same effect.
Long-term effects of too much caffeine can include high blood pressure, anxiety and disturbed sleeping patterns.