The cough reflex is a protective mechanism that helps clear the airways of irritants, mucus, or foreign particles. When the throat, trachea, or lungs are stimulated by these irritants, sensory nerves send signals to the brain, which triggers a forceful expulsion of air from the lungs. This action helps to remove unwanted substances and maintain clear breathing passages. Coughing can be voluntary or involuntary and is often a symptom of various conditions, such as infections, allergies, or asthma. While a cough can be annoying, it plays a crucial role in respiratory health by preventing blockages and infections in the lungs.