Jackie Leonhardt, 16, a junior at Coronado High School, says she didn't like the taste or the smell of the cigarettes at first. She smoked because her friends were always doing it around her.

Leonhardt started getting packs of her own cigarettes purchased for her by older friends. Half a pack a day was her usual habit. Soon, her mom started to catch on because Leonhardt was always reeking of smoke.

Eventually, Leonhardt broke down and told her mother about her secret, promising to quit.

"I try to quit a lot," Leonhardt says, "but when I get stressed out I need a cigarette."

She says that it's a social thing. When someone pulls out a cigarette, it's automatic for her to want one as well.

Her parents used to smoke, which made her more comfortable with being around cigarettes.

Lisa Shapiro, a counselor at Coronado, believes that kids are more likely to smoke if a family member does so as well. She argues that if teenagers have been around cigarette smoke for a while, they are bound to pick up the habit because it has already been in their lungs and they're immune to some of the undesirable qualities.

According to the American Academy of Family Physicians, nicotine is a stimulant that heightens stress because it raises your blood pressure and makes your heart beat faster. When your blood pressure is high, it can hurt blood vessels, arteries and veins, increasing the risk of having heart disease, a heart attack, a stroke and kidney failure.

Still, this doesn't stop some teens from lighting up.

Paulina Klagues, a senior at the College of Southern Nevada, had her first cigarette in the eighth grade because she "felt cool doing it."

"I started smoking because I really liked the image that it put off, and all my friends were smokers," she says.

Like Klagues, most smokers start the habit before they turn 18. Teens usually smoke because their friends are doing it and they're curious about what it's like.

Also, teens enjoy the fact that they appear to be older while doing it.

Klagues smokes anywhere from three to 10 cigarettes a day of her favorite brand, Marlboro 27s. She tried to quit once, but she enjoys smoking because she says it helps calm her down.

"It really becomes a habit," she says. "Every time I get into a car, I smoke. On every break at work, I smoke."

Klagues' parents know she smokes and they hate it. She plans on quitting -- just not any time soon.

Indeed, some teenagers smoke just to go against authority and to spite their parents.

Still, Klagues' health has taken a hit since she started smoking. She runs out of breath quickly. If she doesn't have a cigarette, she gets a headache and experiences mood swings. In the beginning, she had acne breakouts.

In addition to peer pressure and the allure of teenage rebellion, others begin smoking because they think that smoking will help them be more social. Smoking also is popular among those who want to lose weight because it's a stimulant that helps control hunger.

Whatever the reasons for teens to begin smoking, the common bond that unites them all is the long-term damage that smoking can do.

"I don't know why smoking is still considered 'cool,' " says Shapiro. "We know all the harm it does to your body."

And there can be other, more immediate repercussions as well.

If a school administrator catches you smoking or finds evidence of cigarette use, the items will be confiscated.

"On the first offense, the student has a conference with a dean," says Marla Kober, dean at Coronado. "After that, it can lead to a suspension."