Drinking too much caffeine can show up as fatigue, jitters, headaches, heart palpitations, and more. Experts recommend capping your caffeine intake at 400 milligrams a day. If you spot these warning ...

That jittery feeling is a sign to change course, not panic. Drinking too much coffee can overstimulate your nervous system, leading to jitters, anxiety, digestive upset, a racing heart, and sleep ...

Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years of experience in consumer-facing health and wellness content. Experts recommend capping your caffeine intake at 400 ...

While everyone’s tolerance is different, there is a limit to how much caffeine people can have in their systems. Jittery fingers and a racing heartbeat are common signs that you’re over-caffeinated.

The caffeine in energy drinks is higher than what teens should get in a day, Consumer Reports' tests of energy drinks show.

For many Americans, a morning routine is not complete without a cup of joe. The National Coffee Association reports the average American drinks just over three cups daily. And some people opt to get ...