This study investigates the differences between patients with and without obstructive sleep apnea (OSA) in U.S. emergency departments (EDs), focusing on demographics, resource utilization, clinical characteristics, and outcomes.Using data from the 2016-2017 National Hospital Ambulatory Medical Care Survey Emergency Department Subfile (NHAMCS-ED), we analyzed adult ED visits. Patients were classified as having OSA based on documented diagnoses or ICD-10-CM codes. Outcomes included hospital and ICU admission rates, medical resource utilization (e.g., imaging, blood tests), and mortality. Logistic regression was used to adjust for confounders.OSA accounted for approximately 5,985,955 (2.8%) annual ED visits. Compared to non-OSA patients, those with OSA were more likely to be male (adjusted OR: 1.34, 95% CI: 1.14-1.57) and older, with the highest prevalence in the 60-74 age group. OSA patients were more likely to visit for respiratory (16.4% vs. 10.1%) and cardiovascular symptoms (3.5% vs. 2.1%). They required higher levels of care, with elevated hospital (30.3% vs. 13.7%, adjusted OR: 1.27, 95% CI: 1.03-1.58). Resource use was significantly higher, including blood tests (75.0% vs. 54.9%, adjusted OR: 1.58, 95% CI: 1.26-1.98) and imaging (73.1% vs. 53.9%, adjusted OR: 1.30, 95% CI: 1.07-1.59).Patients with OSA represent a distinct subgroup in EDs, characterized by greater resource needs, higher acuity, and worse outcomes. These findings underscore the importance of optimizing care strategies for this population to reduce the clinical and economic burden.Copyright: © 2025 Sun et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.