After a string of lung disease cases linked to electronic cigarettes, doctors across the county are scrambling to make diagnoses.
NBC News reports patients tend to be misdiagnosed with either bronchitis or a viral disease and report feeling lousy for a few days.
Most will experience shortness of breath, fever, cough, fatigue, nausea and vomiting. All have said they recently vaped either THC, nicotine or a combination of the two.
When treatments for the misdiagnosed conditions fail, patients' symptoms worsen to the point where they have trouble breathing, forcing them to seek emergency help.
Findings from officials at the Wisconsin Department of Health published last week found misdiagnosis was common in Illinois and Wisconsin, and by the time patients were hospitalized, more than half needed to be placed in intensive care. A third of them had to be put on ventilators.
Doctors are recommending people who vape to seek medical help if they start developing symptoms like shortness of breath, coughing, fever, chest pain, extreme fatigue, vomiting or diarrhea.
The Food and Drug Administration has tested 120 vaping product samples, but have so far been unable to identify a single brand, ingredient or substance that could explain the illness.
While the investigation is underway, consumers are urged to steer clear of potentially counterfeit products.
Investigators are also urging people who have symptoms to report them at the government website: www.safetyreporting.hhs.gov.