Yes, it can cause heart attacks, quickened heartbeat, and irregular heartbeat due to the high amounts of caffiene, it can cause you to become jittery because of the caffeine, you can become addicted to it, you can also go into sugar shock due to the high dosage of sugar, and it can cause strokes in some, it also messes with your sleep cycle. Also, though they 'quench' your thirst, they actually rob you of hydration and if you do not drink enough water, you can become severely dehydrated, which can be fatal. Now these things happen if you drink them every day and in high volume (such as my friend who drank 4-6 a day and nearly died of dehydration and sleep deprivation and now is banned from drinking them because the doctors are afraid for her heart). Also, over time your body becomes accustomed to that caffeine amount and needs more. One of them every so often won't really hurt you in the long run but binging on them every day is not good for you.
