Which of the following is NOT typically considered an airway obstruction?

The effective cough reflex is not typically considered an airway obstruction because it functions as a protective mechanism that helps keep the airway clear. When the airway is obstructed, the body tries to resolve the issue, and coughing is a natural response to expel any foreign material, mucus, or other obstructions from the respiratory tract.

In contrast, a foreign body in the airway, swelling of tissues (such as in an allergic reaction or anaphylaxis), and fluid in the lungs (as seen in conditions like pulmonary edema) can all lead to significant airway obstructions. They interfere with normal airflow and can cause respiratory distress or failure, making them critical concerns in emergency situations. Thus, while the other options indicate potential airway obstructions, an effective cough reflex signifies an intact air passage that can clear obstructions rather than being an obstruction itself.