The longer a person or animal stays awake; the urge to sleep becomes stronger. This is known as sleep pressure and is triggered by a chemical called adenosine. Adenosine accumulates in the brain when the human is awake which helps to stimulate the patterns of brain activity that occurs during sleep. As the day processes, the brain releases more adenosine through receptors, which makes you feel sleepy during the night. One common method to prevent sleepiness for a period of time is to consume caffeine. The stimulant is the most widely used psychoactive substance and can be found in common beverages such as energy drinks and coffee. Although caffeine can benefit humans by enhancing physical performance and reducing pain, serious concerns have been raised about health risks associated with caffeine’s effects on human health and the brains chemistry.