Respiratory ailments are illnesses that affect the lungs and airways. CROUP is a viral infection of the larynx, trachea, and bronchi, which is characterized by a harsh, barking cough. Asthma is a chronic inflammatory disorder of the airways that can cause difficulty breathing, wheezing, chest tightness, and coughing. The FLU is an infectious disease caused by a virus, which can cause fever, chills, body aches, and respiratory symptoms such as coughing and difficulty breathing.