Primavera otoño 2020 (Año LXIII Núms. 122-123) Año LXIV Núm. 124-125 horizontes PRIMAVERA / OTOÑO 2021 PUCPR 49 EFFECTS OF DEEP BREATHING: NON- PHARMACOLOGICAL INTERVENTION FOR ANXIETY Lorreine M. Zayas Rodríguez Pontifical Catholic University of Puerto Rico Neuroscience Master’s Degree Program Abstract This review article will describe how deep breathing therapies help manage mental disorders such as anxiety and heart rate. Deep breathing is a therapeutic method for various scenarios that cause anxiety, such as for children and adult students before exams and patients undergoing medical procedures. Health professionals, such as psychologists, can practice these therapies to improve their professional performance. Deep breathing decreased heart rate, increased concentration, increased efficiency, and increased self-control. Some studies have obtained favorable results by developing and enhancing technology with deep breathing methods. In conclusion, deep breathing therapy helps decrease indicators and symptoms of anxiety and depression. Introduction Anxiety is a state of mind that causes physical, mental, and biological changes in the human body. The patient with anxiety presents a series of physiological changes resulting from stress buildup. Symptoms may include sweating, increased heart rate, hyperventilation, altered thoughts, fear, insomnia, and bodily tremors. Non-pharmacological treatments include relaxation techniques. Several studies have shown positive physiological modifications in anxiety patients after using deep-breathing techniques. Respiratory and cardiac systems are affected by oxygen volume, which reaches the nerve and surrounding tissues. Inspiration (ventilation phase when air enters the lungs) increases abdominal pressure and decreases intrathoracic pressure. An increase in intrathoracic pressure from deep breathing results in decreased inspiration and expiration (ventilation air exits the lungs) rates. The Valsalva maneuver increases the oxygen concentration, reaching the patient's nerves and tissues covering his mouth and nose while attempting to exhale forcefully. The Valsalva maneuver may influence the heart to regain a normal rhythm. Deep breathing, including the Valsalva maneuver, has demonstrated that inspiration and expiration directly intervene in the body's physiology. Combining meditation with deep breathing allows the individual to control his body and effectively manage depressive and anxiety disorders. Some scenarios result in people sharing similar anxiety characteristics, including losing control of their thoughts or developing physiological body stress. These scenarios include taking examinations, suffering from a disease, undergoing surgery or treatment, or experiencing childbirth. Deep breathing requires a degree of concentration, coordinated movement, and positive thinking relating to the circumstances causing anxiety. Improvements include critical thinking, decision making, and task-execution capabilities. Deep breathing is a technique that should continue to be studied. However, this non-pharmacological treatment is already an effective treatment against anxiety. Main analysis Anxiety causes many symptoms that result in people not performing their functions properly. Many researchers have looked for different treatments to improve this condition. Among the non-pharmacological alternatives, there is the well-known deep-breathing