Abstract
Chlorine, a dense and irritating gas used in pool disinfection, can cause severe respiratory issues, including airway damage, alveolar injury, pulmonary edema, and chronic conditions such as bronchiolitis obliterans. This case study describes a patient initially thought to have hot tub lung (HTL) due to symptoms, hot tub use, and imaging findings. However, negative Mycobacterium tests and significant chlorine exposure led to a revised diagnosis of chlorine-induced lung injury. The diagnosis was further supported by the patient's clinical improvement and prior normal lung scans.