How many cups of coffee will kill you?

If you can't start your morning without a cup of joe, you aren't alone, but if you find yourself drinking more than six cups of java a day, you could be putting your health in danger.

According to the Diagnostic and Statistical Manual of Mental Disorders, "caffeine intoxication" does exist. Caffeine blocks neurotransmitters such as dopamine and norepinephrine in the brain while triggering stimulating chemicals that give coffee drinkers that jolt.

Some people can get edgy from one cup of coffee while others need a few to feel the symptoms of too much caffeine, which include insomnia, nervousness and increases in energy.