ABSTRACT
Nasal obstruction or nasal blockage is the sensation of reduced airflow through the nose and can be bilateral or unilateral. In normal respiration, the physiological pathway is via the nose, and the sensation of nasal obstruction occurs when this process is impaired. If this is severe, mouth breathing will also be evident. In emergency situations, and during extreme exercise, the higher ventilation requirements mean that physiological mouth breathing may have to come into play, as a necessary supplement to nasal respiration. Occasionally, athletes may become concerned about this and are best reassured that it is not unusual to have to resort to some mouth breathing during exercise. Normal physiological changes mean that nasal patency can be influenced by factors other than exercise. These include the humidity and temperature of the surrounding air and the position of the body, with the supine position being associated with more congestion when compared with being erect. The average rate of ventilation during nasal breathing at rest is approximately 6 litres per minute. During exercise, this will increase to 50-60 litres per minute, and at this level will be shared jointly as nasal and mouth breathing.
