Every day almost every american, 90% of us, consumes caffeine in coffee, in tea, in soda and lately increasingly in energy drinks. Well, tonight a lawsuit alleged one of those energy drinks could be... See More
Every day almost every american, 90% of us, consumes caffeine in coffee, in tea, in soda and lately increasingly in energy drinks. Well, tonight a lawsuit alleged one of those energy drinks could be linked to a death raising a question, how much caffeine is too much? Abc's senior national correspondent jim avila gets answers. Reporter: Everyone knows caffeine can create a body buzz, make the hands shake, hearts palpitate but in high doses like those found in the energy drink monster, can it kill? The fda says it's received reports of five deaths and one heart attack possibly linked to the energy drink and it is investigating diligently, but is not confirmed they were caused by monster. She had no pulse but her heart was still beating. Reporter: Wendy's daughter anais died six days later and is one of those five deaths the fda She had a 24-ounce monster. That was it. Reporter: This picture of a too young to die teen has been the rallying call for a crackdown of energy drinks accused of marketing their hyper caffeinated drinks to young people. Senator dick durbin held it up in the senate. She drank two 4-ounce drinks and it took her life. Reporter: Is it true for caffeine to be the true killer. The death certificate says caffeine toxicity. Monster is way up near the top of the list. More than a starbucks latte. More than four cokes. And the energy drinks are built to chug, they even have large ings in the can. We've seest of health risks associated with the consumption of energy drinks and not necessarily coffee. And one of the reasons for that could be that coffee is consumed while it's hot and more slowly. Reporter: But here's the thing. The adult lethal level of caffeine generally recognized by doctors is 5,000 to 10,000 milligrams and it would take 31 to 62 cans of the 16-ounce monster drank one after another to reach that point. Still physicians warn all that changes with people who respect healthy adults such as children with underlying conditions like high blood pressure and heart trouble as anais had. As for monster it says they've sold 8 million energy drinks and is unaware of any father facility anywhere caused by its drinks. Jim avila, abc news, new york.
This transcript has been automatically generated and may not be 100% accurate.