Obstructive sleep apnea (OSA) is a heterogenous disease process that cannot be adequately categorized by AHI alone. There is a significant prevalence of OSA in the general population with ongoing efforts to evaluate the risk factors contributing to OSA and its associated clinical implications. Only by improving our understanding of OSA can we advance our methods in the diagnosis and treatment of OSA. For this article, the authors reviewed keywords of obstructive sleep apnea diagnosis and therapy in the databases of Embase, Medline, and Medline ePub over the past 3 years, excluding any articles that only addressed sleep apnea in children under age 17 years. This review article is divided into three main sections. First, we will investigate the use of novel screening tools, biomarkers, anthropometric measurements, and novel wearable technologies that show promise in improving the diagnosis of OSA. There is mention of comorbid conditions seen in OSA patients since certain disease combinations can significantly worsen health and should raise our awareness to diagnose and manage those concomitant disorders. The second section will look at the current and developing treatment options for OSA. These include positive airway therapy (PAP), mandibular advancement device (MAD), exciting new findings in certain medications, orofacial myofunctional therapy (OMT), hypoglossal nerve stimulation therapy (HGNS), and other surgical options. We will conclude with a section reviewing the current Clinical Practice Guidelines for Diagnostic Testing in Adults with Obstructive Sleep Apnea from 2017, which strongly advises polysomnography (PSG) or home sleep apnea testing (HSAT), along with comprehensive sleep evaluation for uncomplicated patients with a clinical presentation of OSA.