1. Brain Caffeine blocks sleep-promoting chemicals from being received by the brain. 2. Heart Increased heart rate and irregular heartbeat can occur from drinking large amounts of caffeine. 3. Arteries Caffeine stimulates the heart to pump harder, increasing blood pressure. 4. Stomach Digestive system disturbances can occur from drinking caffeine. 5. Mind Anxiety can result from the mental and physiological disturbances caused by heavy caffeine use. Sleep disturbances are common in heavy caffeine drinkers, especially if caffeine is used right before bedtime. Catie Connors and Angela Solomon