Caffeine is a stimulant that affects the central nervous system
Though caffeine’s main affect is to make your body feel more awake and alert, it also can cause the following issues:
High blood pressure
Jittery, shaky feelings
Rapid heart beat
Uneven heart rhythm
The effects of caffeine usually last about four to six hours, and can cause an overdose if consumed in extremely high levels
Caffeine itself is a stimulant with some positive and negative effects. It makes most of us feel more alert, awake, and focused, but too much can also backfire.
It also affects a host of processes in our bodies, including our digestion, metabolism, and vision.