When Cassandra Miles’ fiance’s cheeks were sunken in and his once-white skin turned gray, Miles began to worry.

After confronting him about his appearance, Miles, a journalism senior, learned her fiancǸ was drinking large amounts of Rockstar and Monster, two popular energy drinks full of caffeine.

He said he had been drinking a lot of them because of finals at school, Miles said.

He only slept a few hours each night that week because he was taking 20 units in addition to working a part-time job, Miles said.

Miles’ fiance is one example of the many students overburdened by school and work who depend on high levels of caffeine to get through the day.

But excess amounts of caffeine in a short period of time can have harmful side effects on the body.

Increased heart rate, excessive urination, nausea, vomiting, restlessness, anxiety, tremors and difficulty sleeping are some side effects too much caffeine can have on the body, said Keith Boesen, a Certified

Specialist in Poison Information from the Arizona Poison and Drug Information Center.

The average daily “”threshold”” of safe caffeine intake is 300 milligrams, said David Salafsky,

harm and risk reduction coordinator for UA Campus Health Services.

The number differs per person, and is also based on tolerance, but anything over 300 milligrams per day can consistently affect your health, Salafsky said.

Yet, despite the dangers of overdosing on caffeine, some students are oblivious to the high quantities of caffeine in the products they drink.

According to snopes.com, one can of Red Bull, one of the most popular energy drinks on the market, contains 80 milligrams of caffeine, more than twice as much as a can of Coca-Cola Classic.

According to their official Web sites, one 16-ounce can of Rockstar contains 160 milligrams, while Cocaine has 294 milligrams of caffeine per can.

In contrast, an 8-ounce brewed cup of coffee contains about 85 milligrams of caffeine, while an 8-ounce imported tea has about 40 milligrams of caffeine, according to the International Food Information Council Foundation.

Students said they drink these caffeine-loaded drinks in order to stay awake during the day.

“”We live in a 24-hour world,”” Salafsky said. “”People have to stay awake and they take caffeine to get their things done.””

Undeclared freshman Lindsay Young said she drinks a cup of tea every day.

“”I don’t need to drink it, but I do feel lively after I do,”” she said.

A noisy roommate who keeps the light on factors into Young’s lack of sleep. But Young isn’t the only student who suffers from lack of sleep.

Sixty percent of UA students said they get a “”fair amount”” of sleep, but 54 percent said they have fallen asleep in class or had trouble staying awake while driving or engaging in social activities, according to a UA sleep survey conducted by Campus Health.

But students who drink caffeine to stay awake often can’t fall asleep when they want to.

“”When I drink more caffeine (than usual), it makes it worse for me to fall asleep,”” Young said.

Salafsky credits the problem to the “”indirect cost of sleep deprivation.””

“”The body cannot get into a deep rest while sleeping,”” he said.

Salafsky said the problem is clear: Students drink caffeine to stay awake through demanding schedules, but often don’t realize the consequences.

“”Drinking caffeine is a Band-Aid approach to a greater problem of the central sleep issue,”” Salafsky said.