Transcript for Doctors who first saw signs of vaping epidemic speak out
We move to our "Gma" cover story. As the death toll grows from vaping a new report from the mayo clinic say some are seeing injuries that are similar to Kim Cal burns. . Good morning. It's absolutely right. Four months ago doctors did not even have a term for the kinds of lung illnesses they're seeing today called vaping. Now medical experts are say e-cigarettes have become a habit that is far too dangerous. This morning, another vaping-related death. Alabama announcing their first fatal case marking the 18th death nationwide. The CDC also reports nearly 40% of the more than 800 probable cases of vaping-related lung injury are aged 21 or younger. The first to connect all these illnesses and deaths to vaping were doctors in Wisconsin. Most of the patients that came into the hospital and required more intensive services were having breathing problems and that was being presented as shortness of breath, coughing, unexplained weight loss, fatigue. Reporter: The physicians fighting four teenagers worried they may have an outbreak on their hands. The concern that this was a potential public health issue, and we were concerned that it was bigger than just children's hospital of Wisconsin. Reporter: Doctors ran tests conducting a social history, asking the teens about their lives and habits to determine what could be making them so sick. It's very important to be honest and to tell your trusted health care provider all the details that you can think of related to vaping especially if you're experiencing an unexplained cough, weight loss, fatigue, or other respiratory symptoms. Reporter: Using that history the doctors learned all four of the youth had been vaping. It was clearly an issue in the country and it needed something to kind of start it rolling. And we were fortunate enough to be that starting point. Reporter: The CDC says that most of the lung illnesses associated with vaping in these cases involve thc with or without nicotine. No specific product or device is associated with all the illnesses but doctors are now urging people to stop vaping altogether. Nothing other than air should be inhaled. That's a strong statement a note for parents too because e-cigarettes don't smell like smoke, flavors mask the habit. One mom said she had no idea her daughter was using vapes. It smelled like a candle coming from her room. It is everywhere. Thanks very much.
This transcript has been automatically generated and may not be 100% accurate.