2. Drinking Coffee Drinking coffee has become a habit of most modern citizens. Surprisingly, 90% of people in the United States drink it everyday. It is thought that drinking coffee facilitates working efficiency since coffee contains a stimulant - caffeine - which stimulates your brain and keeps you awake. It helps people to work longer in consciousness. A cup of coffee is good for health, however, consuming too much coffee will lead to some serious diseases, such as high blood pressure, insomnia and uncontrollable tremor. There are also some withdrawal symptoms when you give up drinking coffee, if you are a coffee addict, for example, you will feel very lethargic and get headaches. Therefore, it is suggested that drinking coffee only in a moderation.