Walk through grocery and convenience stores and you'll see a dizzying array of energy drinks. In fact, energy drinks have become a billion-dollar industry in North America as a quick "pick-me-up," and many make other unsubstantiated health promises.

These drinks may seem harmless; after all, you can buy them almost anywhere. However, recent reports indicate a dramatic increase in serious health issues as a direct result of energy drink usage.

Here are 5 reasons to be cautious:

1. Hospital visits: Too many energy drink enthusiasts end up in hospitals because of shakiness, seizures, heart palpitations and other symptoms. The number of ER visits involving energy drinks doubled from 2007 to 2011. It's not just teenagers and young adults who are most likely to be affected; the biggest jump in ER visits (279%) was in the 40-plus age group. And children under the age of 6 account for half of all calls to poison control centers due because of energy drink toxicity!
2. Excess sugar: Some energy drinks have more than 10 teaspoons of sugar in a 12-ounce serving. According to the U.S. Department of Health and Human Services, people who consume drinks with added sugars consume more total calories, and studies have found that drinking sweetened beverages is related to weight gain. "Zero calorie" energy drinks that are filled with artificial sweeteners are no better for your health.
3. High blood pressure: Just two energy drinks a day can cause dangerously high blood pressure, including a faster heartbeat and a major jump in systolic (maximum) blood pressure.
4. Heart problems: A 2010 American Journal of Medicine study found that just one energy drink can cause blood vessels to narrow, even in healthy young people. The culprit is often a commonly-used sweetener in sugar-free energy drinks.
5. Headaches: This is one of the most common side effects reported by energy drink users. A recent report found that over 20 percent of people who use energy drinks reported headaches, and almost a third suffered from "jolt-and-crash" episodes-sudden bursts of energy followed by a major "crash."

Facts to note if you consume energy drinks:

• On average, caffeine takes 15-20 minutes to perk you up and lasts for 4-6 hours.
• Caffeine dehydrates your body so additional water should be consumed, especially under hot conditions or if you're working out.
• Pregnant women should exercise caution when consuming caffeine.
• A person's tolerance for caffeine will increase over time so that they may have to consume more in order to continue experiencing its "good effects." (To avoid developing caffeine tolerace, consume it only every third or forth day.)
• Caffeine can become addictive. If one tries to cut back too quickly, they may experience symptoms such as headaches, depression and/or irritability.
• Drinking the caffeine equivalent of more than a couple cups of coffee per day puts a person at increased risk of developing osteoporosis.
• Unlike hot coffee, which we normally sip, energy drinks are more conducive to gulping which puts a person at greater risk of caffeine over consumption.