With finals week less than three weeks away, many students may find themselves indulging in caffeine to pull all-nighters to study. But an extreme increase in caffeine consumption can have negative side effects.

Allison Gering, a fifth-year in middle childhood education, is no stranger to all-night studying for exams, having done so multiple times during her five years at Ohio State. She said she drinks four cups of coffee a day, and increases her caffeine intake during exam week to get more work done.

Gering said she isn’t fazed by caffeine’s side effects.

“I mean, it’s distracting, but you don’t sleep, so that’s good,” Gering said.

But added energy with less sleep is not the only result of increasing one’s caffeine dosage.

Including insomnia, too much caffeine can lead to side effects like irritability, nausea, increased nervousness, muscle tremors and increased heartbeat, said Angela Blackstone, a registered dietician at the Center for Wellness and Prevention at OSU.

“Also, caffeine does act as a diuretic … so make sure that you’re drinking plenty of water in addition to any caffeinated beverages that you drink,” Blackstone said.

Blackstone, who completed her education at OSU’s School of Allied Medicine and Dietetics, has been at the university for 13 years.

Of course, these side effects are largely dependent on a person’s tolerance for caffeine, the amount of it being consumed and the concentration of the substance in each form.

It can take up to an hour after consuming a caffeinated beverage for one to feel energized, but the effects can last for three hours or longer, Blackstone said.

A moderate daily dose of caffeine for an adult is 200-300 milligrams, or two to four cups of coffee per day, Blackstone said. Unhealthy doses are 500-600 milligrams or five to seven cups of coffee daily.

Andrew Nielsen, a fifth-year in art history, is at the top of the healthy dose limit.

“I do two large cups of coffee in the morning Monday through Saturday and that’s it,” Nielsen said.

Though she doesn’t specifically know of someone hospitalized for side effects of an increased caffeine dosage, Blackstone said it isn’t an unlikely occurrence.

“If there’s someone that has heart problems, we tell them to talk with their doctors,” Blackstone said, “(Caffeine) being a stimulant, if they’re taking something that helps to control their heart rate, it could cause more problems.”

Caffeine comes in multiple forms: coffee, energy drinks, energy shots and tablets are among the most common. However, Blackstone said the side effects from all are relatively the same, and vary with dosage and concentration.

Energy shots and caffeine tablets have a more concentrated dose of caffeine than a cup of coffee or energy drink and those effects can feel more severe and appear faster, Blackstone said.

“If the caffeine content is a lot higher, say like in an energy shot versus a cup of coffee, then you might expect the symptoms to be worse, like the irritability or the shakiness,” Blackstone said.

Some energy drinks, like Rockstar or Monster, contain guarana, a compound with properties similar to caffeine.

Depending on which part of the plant is used, guarana can have an effect more powerful than caffeine in a regular cup of coffee. The seeds of the guarana plant are most concentrated and have the biggest effect. Both Rockstar and Monster contain guarana seed extract.

But unlike caffeine, guarana is classified as an herbal supplement and is not regulated or evaluated by the Food and Drug Administration.

“It makes it a little harder, because if a product says it has that in it, sometimes you don’t know what part of the plant it’s coming from,” Blackstone said.

The severity of these side effects depends on a person’s tolerance for caffeine, Blackstone said. Students who don’t consume a lot of caffeine on a regular basis would be more likely to experience side effects of increased caffeine consumption.

Blair Swager, a first-year in civil engineering, only drinks coffee about twice a week, when she has studying to do. Though she doesn’t always notice other side effects, Swager said her sleep schedule and energy levels are definitely affected.

“It makes me really awake, and then later I feel really extra tired and crash,” Swager said.

Blackstone recommends keeping a healthy diet, exercising and getting enough sleep during exam week, rather than overdoing the coffee.

Nielsen agrees with Blackstone’s statement, and plans on taking some of that advice.

“I used to stay up super late, but as I got older, I was just like, ‘you know what, screw this. I’ll just wake up early.’ And so I just go to bed and if I don’t get the studying done, I just don’t get the studying done. It’s not worth it,” Nielsen said.