Caffeine poisoning comes after consuming too much of the substance, doctors say

How much coffee is too much? 500 to 600 mg of caffeine, experts say. Photo: ABC7

(CNN) - Caffeine, as we all know, is an addictive drug that millions of Americans consume on a daily basis, but doctors say that having too much can lead to serious health problems.

Consuming a large amount of caffeine has given almost everyone the shakes to a lack of sleep - these symptoms are common, after all - but overdosing on the substance is an increasing problem.

Caffeine poisoning, as it's called, is a very real possibility if you consume more than 500 to 600 mg per day. According to the National Institutes of Health, symptoms of poisoning include trouble breathing, convulsions, fever and hallucinations.

Those who experience caffeine poisoning can also experience hallucinations and an irregular heartbeat.

It doesn't take much to get to that critical amount of caffeine as well. Doctors say that depending on the strength of your brew, it could only take about 2 to 4 cups of coffee to get to that threshold. Experts say that keeping your intake between 200-300 mg per day is ideal.

Health groups point to a surge in visits to emergency rooms over the past few years, but many of those have specifically been tied to the consumption of high-caffeine energy drinks. Monster, for instance, contains 240 mg of caffeine in its 16-oz. Cans.

Some scientists say, though, that you'd have to down "a pot" of coffee to experience extreme symptoms.