INDIANAPOLIS, Ind. -- Doctors are warning that the lungs of people who vape are rapidly starting to revolt.
X-rays and chest scans are showing significant lung damage in hundreds of patients struggling to breathe, pulmonologists said.
"Stop vaping now, until further information about what is causing lung damage and death can be understood," said Dr. Barbara Ferrer, director of the Los Angeles County Department of Public Health.
The warning comes after Indiana health officials confirmed another adult died from vaping-related lung problems.
RELATED: Illinois resident who vaped dies after being hospitalized for respiratory illness, health officials say
The death announced Friday by the Indiana State Department of Health is the state's first and the country's third tied to the use of electronic cigarettes.
Indiana officials said the death involved a person older than 18, but that no additional information about the patient will be released.
A fourth death linked to vaping was confirmed by public health officials in Los Angeles County later Friday morning. Health officials there said a total of 12 cases of vaping-associated pulmonary injury, or VAPI, have been reported in the area.
Previous deaths have been reported in Illinois and Oregon.
RELATED: Oregon death is 2nd linked to vaping; 1st tied to pot shot, marijuana oil
Adam Hergenreder vaped for a year and a half. He's been in a hospital bed in Libertyville, Illinois, hooked up to oxygen for nearly a week.
"I'm 18-years-old and my lungs are like a 70-year-old's," Hergenreder said.
The Centers for Disease Control and Prevention said it's now investigating 450 cases of serious lung illness in 33 states.
The agency said that many, but not all, patients recently used products containing THC, the compound that gives marijuana its high. But some reported using both THC and nicotine.
The illnesses have all been reported this year, and the number has been growing quickly in the last month as more and more states have begun investigations. A week ago, U.S. officials pegged the number at 215 possible cases in 25 states.
It's also unclear whether such illnesses were happening before this year.
"We're all wondering if this is new or just newly recognized," Dr. Dana Meaney-Delman of the Centers for Disease Control and Prevention told reporters Friday.
Also on Friday, the New England Journal of Medicine released a series of articles that give medical details about cases reported in Illinois, Wisconsin and Utah.
An article on 53 illnesses in Illinois and Wisconsin noted that nearly one-fifth of the cases were people who said they vaped nicotine and not anything that contained THC or CBD oil.
For that reason, doctors and health officials are continuing to suggest people stay away from all vaping products until the investigation establishes exactly what's at the root of the illnesses.
Symptoms have included shortness of breath, fatigue, chest pain and vomiting. Doctors say the illnesses resemble an inhalation injury, with the body apparently reacting to a caustic substance that someone breathed in.
WLS-TV contributed to this report
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