At a minimum, you may feel more energetic, but over time, too much caffeine may cause withdrawal symptoms. Caffeine acts as a central nervous system stimulant. When it reaches your brain, the most noticeable effect is alertness. Studies have also found that people who drink coffee regularly have a lower risk of developing Alzheimer’s and dementia, and cut suicide risk by 45 percent. These benefits are limited to people who drink high-octane coffee, not decaf. Extra caffeine doesn’t get stored in your body either. It’s processed in the liver and exits through your urine. Caffeine can make your blood pressure go up for a short time. If you consume too much, caffeine may cause also your muscles to twitch.
An overdose of caffeine may cause rapid or irregular heartbeat and breathing trouble. In rare cases, caffeine overdose can result in death due to convulsions or irregular heartbeat.