The chemicals in an e-cigarette can sometimes cause a condition called wet lung.
An 18-year-old woman was hospitalized in May after she developed a cough, difficulty breathing, stabbing pains in the chest, and upper respiratory problems, according to a report in the journal Pediatrics.
The chemicals in the e-cig caused inflammation in the lung, causing the body to mount an immune response. The immune response caused fluid to accumulate in the lungs.
Researchers do not know how common this response is.
