We all know the dangers of smoking cigarettes.

Doctors say smoking is the leading preventable cause of death and kills a half a million people in the U.S. every year.

Electronic cigarettes are helping a number of people stop smoking combustible cigarettes, but pulmonologists say that doesn’t mean they’re good for your health.

“It was made to help people get off of combustible cigarettes,” explained Dr. Mark Johnson, a pulmonologist with Covenant Health. “But now, it has a mind of its own. There are reasons to be very concerned about its use.”

E-cigarettes are highly addictive, increase your heart rate, and enhance the growth of cancer.

Dr. Johnson says those are just a few of the dangers. 

But there aren’t any studies looking at the long term effects, yet. 

“It wouldn’t surprise me in 20-30 years from now that we are talking about vaping lungs,” said Dr. Johnson.

He says one of the biggest dangers is the number of kids using them.

“It’s going into epidemic proportion,” explained Dr. Johnson. “The number of underage kids using it has gone up by like 800% in the last year. It’s increased by 80% in high school students and 50% in middle schools and it’s a huge problem.”

Dr. Johnson said if you are a parent, the best thing to do is talk to your kids about the dangers of e-cigarettes and how addictive nicotine is.

“It’s as addictive as heroin,” said Dr. Johnson. “Once they are hooked on it, the fear is that they will then start smoking.”