There are several lung injuries that have been associated with e-cigarette use. These include injuries associate with nicotine use, lung injuries associated with other chemicals that may be found in vape juice, and addiction.
Injuries Associated with Nicotine Use
One of the injuries that may be associated with vaping is nicotine poisoning. Nicotine poisoning occurs when you have too much nicotine in your body to the point it becomes toxic.  Since vaping refill pods often contain 20x the amount of nicotine as one cigarette, a person may intake a much higher dose in one setting simply by accident.  Symptoms of nicotine poisoning or nicotine toxicity include: seizures, convulsions, blood clots, pulmonary embolism, high or elevated blood pressure, stroke, pain in the joints, and/or other heart diseases.
Lung Injuries Associated with Other Chemicals in Vape Juice
There have been other concerns over the potential harms caused by vaping related to what may be found in the vape juice itself. Vape juice is sold by a number of companies in bottle and pod forms for refill purposes. The Journal of Pediatrics did a study that found several cancer-causing chemicals such as formaldehyde, acrolein, and toluene in the juices researched.
Additionally, when vape juice is heated by the electronic nicotine delivery system, a reaction may produce certain metal particles that are then inhaled and lodged in the insides of the lungs. A condition known as popcorn lung has been associated with E-Cigarette use as well. Symptoms of popcorn lung include coughing, wheezing, shortness of breath, and other respiratory issues.
Nicotine Addiction
Yes. One Juul pod contains as much nicotine as an entire pack of cigarettes.  That is a massive dose of nicotine in each Juul pod. Middle school and high school-age children are drawn to the fruity and candy flavors only to find that these e-cigarettes are just as if not more addictive as smoking cigarettes.  Nicotine addiction can be costly to treat and take years to completely overcome.