From 2007 until 2011, there were an estimated 10,000 ER visits linked to energy drinks. That number grew to 20,000 in 2011.
The report by the Substance Abuse and Mental Health Services Administration says energy drinks can cause insomnia, nervousness, headache, fast heartbeat and seizures.
The energy drink industry says its beverages are safe, and there is no proof linking its products to the reactions.
