Pathophysiology
• Tracheitis and bronchitis with accumulation of mucus, inflammatory cells, bacteria, and dead epithelial cells
• Valsalva Maneuver. When a person forcefully expires (coughs) against a closed glottis, changes occur in intrathoracic pressure that dramatically affect venous return, cardiac output, arterial pressure, and heart rate - sometimes causing hemorrhages in conjunctiva and brain
• Leukocytosis – predominance of lymphocytes
• Infection rarely extends to lung (to cause pneumonia) or to ear (to cause otitis media), never cause bacteremia