The term “energy drinks” refers to beverages that contain caffeine in combination with other ingredients such as taurine, guarana, and B vitamins, and that claims to provide its consumers with extra energy.

In the past year, energy drink consumption has been linked to several deaths. Including 14 year-old Anais Fourner, from Maryland, who died from a heart attack due to caffeine toxcity after drinking two cans of Monster energy. The FDA is investigating her death, along with four others linked to the Monster energy drinks.

Here are five useful facts to know about energy drinks.