Respiratory diseases are conditions that affect the organs and tissues involved in respiration or breathing. The respiratory system is made up of: the nose, pharynx, larynx, trachea, bronchi, and lungs. Respiratory conditions are usually either infectious or chronic. An infectious respiratory condition is most often either bacterial or viral, such as the common cold or flu. Chronic respiratory conditions are long lasting and can re-occur such as asthma or chronic obstructive pulmonary disease. Respiratory conditions can vary greatly in severity from mild symptoms to more serious conditions.