Hundreds of people across the country have contracted severe vaping-related lung disease and a handful have died, according to public health officials. Many were healthy young people in their teens or early 20s. Researchers from many states are working with the federal Centers for Disease Control and Prevention and the Food and Drug Administration to find out why.
Here's what we know so far.
Who is at risk?  Anyone using electronic cigarettes or other vaping devices, whether consuming nicotine or substances extracted from marijuana or hemp, may be at risk, as investigators have not determined whether a particular device or type of discharge fluid is responsible. .
F.D.A. issued this statement: "Because consumers cannot be sure whether a THC vaping product may contain vitamin E acetate, consumers are urged to avoid buying vaping products on the street and refrain from using THC oil or modifying / adding substances in products purchased in stores. "
But some of the patients who became ill said they had not evaluated THC. In 53 cases of the disease in Illinois and Wisconsin, 17 percent of patients said they had used only nicotine products, according to an article in the New England Journal of Medicine on Friday .
magazine article warned, "e-cigarette aerosol is not harmless; it may expose consumers to substances known to have adverse health effects, including ultra-fine particles, heavy metals, volatile organic compounds, and other harmful ingredients. "
The health effects of some of these chemicals are not fully understood, the researchers wrote, even though the products are already on the market.
What are the symptoms?
Early symptoms include fatigue, nausea, vomiting, coughing and fever, escalation to shortness of breath, which can become so extreme that it can cause an emergency to visit the room or need hospitalization.
Some patients require additional oxygen, including a ventilator, in almost one-third of the cases analyzed in The New England Journal of Medicine.
In lung scans, the disease appears to be bacterial or viral pneumonia that has invaded the lungs, but no infection has been detected in testing.
What is the best way to prevent the disease?
H ealth of fic ials say that the most risky behavior is the use of vaping products purchased on the street instead of a retailer, or those that have been forged with or mixed.
Mitch Zeller, director of the FDA's Center for Tobacco Products, said: "If you are thinking of buying any of these products on the street, outside the back of the car, from the trunk, in the alley, or if you will go home and make product modifications yourself, think of something you purchased from a third party or received from a friend, think twice. "
The CDC and some public health officials recommend that people give up vaping of any kind until the cause of the damage to the lungs is identified.
Electronic cigarettes and other exhaust devices have been developed to help cigarette smokers quit their dangerous habit by providing a way to satisfy their nicotine addiction without inhaling the toxins coming from burning tobacco. But many medical professionals now believe that even smokers should think twice about turning to electronic cigarettes – and anyone who does not smoke should not smoke.
"Older smokers trying to quit should consult their healthcare provider and use proven treatment," the authors of the analysis wrote in The New England Journal of Medicine.
these discoveries, electronic cigarettes should never be used by young people, young adults, pregnant women and adults who do not currently use tobacco. "
What should I do if I think I have lung disease?
CDC says: "If you are concerned about your health or the health of a loved one who is singing calls an e-cigarette product, contact your healthcare provider or your local Poison Control Center at 1-800-222-1222. " Anyone with shortness of breath that lasts for more than a few hours or becomes severe , he should seek medical help quickly. This is a warning that should not be ignored, doctors say.
Why do health investigators think it is vaping-related?
Health investigators believe that diseases are associated with vaping for several key reasons: Patients are vaped with nicotine or marijuana extracts, or both, and have no infection or other condition that would explain lung disease. Patients are now characterized as ill only if they have been reported to be vaping within 90 days. In many of the reported cases, patients diverged much more recently.
Electronic cigarettes have existed for years. Why is this happening now?
There are several theories. One is that some dangerous chemicals or combinations of chemicals are introduced into the pipeline of vaping products. Public health officials believe that when people drink this harmful cocktail, it causes a dangerous, even deadly, reaction in the lungs. These officers have repeatedly said that they do not yet know what substance or device can trigger this reaction and this is the subject of an urgent investigation.
A second theory is that this syndrome is not really completely new and that some people have become ill earlier, but this condition has not been recognized and identified as being associated with vaping. With the increasing popularity of vaping – with both nicotine and marijuana – more cases may arise.
For the time being, however, public health officials seem to believe that the first theory is more likely, and they are looking for a substance, substance or process that could explain the onset of disease.