Energy drinks contain very high amounts of sugar and caffeine, which in high amounts can be dangerous.

• Studies have found the caffeine increases heart rate and blood pressure sometimes to the point of palpitations, which over time can increase the risk of strokes and heart disease.

• Can also lead to nervousness, irritability, dehydration and, like other stimulants, prevent sleep.

• Consuming large quantities may also contribute to weight gain.

• The adverse effects of caffeine on the body can become more pronounced — and more dangerous —when energy drinks are consumed during physical activity, especially in the heat. The combination of fluid loss from sweating and the diuretic quality of the caffeine can leave the user severely dehydrated. The significant increase in heart rate from both the stimulant, caffeine, and the physical activity, can be dangerous.

Both energy drinks and alcohol are dehydrating. Dehydration can hinder your body’s ability to metabolize alcohol and increase the risk of alcohol toxicity. The stimulant effects can mask how intoxicated you are. Once the stimulant wears off, the depressant effects of the alcohol could cause vomiting during sleep or respiratory depression.

Some marketing claims say energy drinks improve performance, concentration, reaction speed, vigilance, emotional status, and metabolism. However, researchers state these claims are unfounded and may even have the opposite effects, like fatigue and dehydration.

Teenagers should limit their caffeine intake to 100 or 200 milligrams per day.

The Food and Drug Administration does not regulate the amount of caffeine in herbal supplements, the category under which energy drinks fall. Also, the manufacturers of these products don’t always list caffeine by name on the nutritional label. Instead, they will use herbal names like guarana, ginseng, ginga biloba and taurine.

People may not realize they are getting caffeine because it’s not on the label, and some energy drinks may contain as much caffeine as 14 cans of soda.