ABSTRACT
RESPIRATION is derived from the Latin word respirare, meaning breathe again. The various clinical disorders of respiration can vary from those that are relatively minor to those that are life-threatening. It behoves the clinician to have a sound understanding of the pathophysiology of these disorders, because life-saving treatment might depend on it. Above all, the clinician should remember that the airway must be patent and that oxygen must be available at all times. It is also essential to remember that the two main functional disorders are defects in ventilation and defects in perfusion. The ability to recognize this in the patient will dictate the diagnostic and therapeutic plan. This is one group of diseases where a tissue diagnosis can be difficult to obtain, thus making it much more important for the clinician to use all available diagnostic information as accurately as possible.
