Caffeine has been used by millions of people across the world every day. It can be beneficial to the body when used moderately, but too much of caffeine can cause problems. Many people take caffeine to reduce physical fatigue and to prevent or treat drowsiness. It can also increase wakefulness, improve focus and concentration as well as better general body coordination. Caffeine – a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines – is a stimulant to the central nervous system. For most adults, taking two-four cups of caffeine a day appears to be fine. However, heavy caffeine use can lead to various problems both physically and mentally, such as insomnia, headaches or dizziness, abnormal heart rhythms, high blood pressure, nervousness, jittery and shaky, chronic arterial stiffness, stomach upset and dehydration. Besides, there is also some evidence that caffeine intake during pregnancy increases a woman’s risk of giving birth to a low birth weight baby. It’s also not a good idea to serve caffeine to children although it may be safe for adults. Perhaps, experts recommend that people in middle to old age should stop drinking tea or coffee after lunch in order to get a good night’s sleep. Unlike many psycho-active substances, caffeine is the most widely consumed psycho-active drug that is legal and unregulated in almost all parts of the world.