Vaping is commonly considered a safer, healthier alternative to traditional cigarettes. This is one of the reasons vapes and e-cigarettes (like Juul's devices) have become increasingly popular among teenagers and other underage users -- not only is there the "cool" factor that's always been associated with tobacco usage, but there's also the dangerous idea that the products are relatively risk-free.

Unfortunately, when something sounds too good to be true, it probably is. Recently, the CDC has been looking into a serious and mysterious lung disease that is apparently caused by vaping. It's not cancer, as far as the organization knows, but it could prove to be just as dangerous. As reported by The New York Times today, the disease has claimed the lives of four American citizens now. The last two victims died in Indiana and Minnesota, respectively.

Officials believe the cause of this disease could be a specific chemical, but they've yet to identify exactly what that chemical might be. However, one of the more likely culprits is a compound called "vitamin E acetate," which was discovered in high concentrations across eight separate cases of this illness in New York.

There's also the possibility that it's a mixture of chemicals that has led to the dilemma: several patients report vaping "substances extracted from marijuana or hemp." These substances (including THC) combined with the chemicals that are in normal vape liquid, could create dangerous "new toxins," Harvard doctor David Christiani theorizes.

Investigators are also looking into potential links between the disease and the use of counterfeit or contaminated vape liquids (and devices) purchased on the street. The CDC, for its part, recommends that the vape-using public avoid such transactions. The organization also says e-cigarette users shouldn't modify their devices in ways that are "not intended" by the manufacturer.

The number of patients that have likely been struck by this illness has doubled recently, to about 450 suspected cases in total. The vast majority (over 80 percent) of patients affected by the disease are men, with an average age of 19.

"We are committed to finding out what is making people sick," said CDC director Robert Redfield in a statement. "All available information is being carefully analyzed, and these initial findings are helping us narrow the focus of our investigation and get us closer to the answers needed to save lives."

The CDC is advising the public to curb their use of vape devices; at least until the group's investigation turns up conclusive results. While we're not medical professionals ourselves, we'd suggest that any of our vape-using readers heed that recommendation in the coming months.