Background: For those with Obstructive Sleep Apnea (OSA), the most effective therapy is continuous positive airway pressure (CPAP). CPAP uses positive airway pressure to keep the patients' respiratory passages open while they sleep (or are awake and breathing normally). End-expiratory alveolar pressure that exceeds ambient pressure is known as a "positive end-expiratory pressure" (PEEP). PEEP is created by CPAP, which maintains a predetermined pressure during the whole breathing cycle, including inhalation and exhalation. It has been shown to lower daytime exhaustion, cardiac risk factors, as well as blood pressure. Objective: The primary therapy for OSA is CPAP. CPAP was evaluated in this study to see if it reduced blood pressure in OSA patients. Research on CPAP and blood pressure in various subgroups of people was analyzed specifically for this study. Methods: Research was carried out through PubMed, Google scholar and Science direct using the terms [Continuous positive airway pressure And Positive end-expiratory pressure OR Obstructive Sleep Apnea]. References from relevant literature, including all identified research and reviews, were also evaluated by the authors, although only studies published between December 2007 and June 2021 were included. Conclusion: Although the overall impact of CPAP on blood pressure is minimal, even modest reductions in blood pressure may benefit in the prevention of cardiovascular events. This impact on those with uncontrolled hypertension merits further investigation. Variability in blood pressure response to CPAP therapy gives an opportunity for more study on this topic. Constant CPAP use has long been associated with an increased risk of hypertension.