(HealthDay News) -- Caffeine is found in everything from morning coffee or tea to lunchtime sodas and afternoon chocolate snacks. It's also found in certain pain medicines, including those taken for headaches.
According to the U.S. National Library of Medicine, caffeine stimulates the central nervous system. It can make you feel more alert, although some people may be particularly sensitive. A caffeine overdose can be caused by taking medications that contain the chemical, combined with too much in your diet.
Side effects from too much caffeine may include headaches, anxiety, nausea, vomiting, rapid heartbeat, irritability, shaking and high blood sugar. Some people may even have abdominal bleeding and diarrhea, the NLM says.
