Most of us consume it every day, but how much do we really know about caffeine? The naturally-occurring substance with a bitter taste stimulates the central nervous system, making you feel more alert. In moderate doses, it can actually offer health benefits, including boosts to memory, concentration, and mental health. And coffee in particular, a major source of caffeine for Americans, has been associated with a host of body perks, including a possible decreased risk of alzheimer's disease and certain cancers.
But in excess amounts, caffeine overuse can trigger a fast heart rate, insomnia, anxiety, and restlessness, among other side effects. Abruptly stopping use can lead to symptoms of withdrawal, including headaches and irritability.
Here are 10 lesser-known facts about one of the most common drugs in the world.