The exact cause of<unk>  is not known, and it is unlikely that a single underlying cause exists. Several contributing factors have been identified, which vary widely among<unk>  patients with different medical histories. Physical exercise (including, but not limited to, competitive athletics) is one of the major triggers for<unk>  episodes, leading to its frequent misdiagnosis as exercise-induced asthma. Other triggers include airborne pollutants and irritants such as smoke, dust, gases, soldering fumes, cleaning chemicals such as ammonia, perfumes, and other odours. Gastroesophageal reflux disease (GERD) and rhinosinusitis (inflammation of the paranasal sinuses and nasal cavity) may also play a role in inflaming the airway and leading to symptoms of<unk>  as discussed below. Laryngeal hyperresponsiveness is considered the most likely physiologic cause of<unk> , brought on by a range of different triggers that cause inflammation and/or irritation of the larynx (voice box). The glottic closure reflex (or laryngeal adductor reflex) serves to protect the airway, and it is possible that this reflex becomes hyperactive in some individuals, resulting in the paradoxical vocal fold closure seen in<unk> . Two major causes of laryngeal inflammation and hyperresponsiveness are gastroesophageal reflux disease (GERD) and postnasal drip (associated with rhinosinusitis, allergic or nonallergic rhinitis, or a viral upper respiratory tract infection (URI)). Rhinosinusitis is very common among patients with<unk>  and for many patients,<unk>  symptoms are ameliorated when the rhinosinusitis is treated. GERD is also common among<unk>  patients, but only some experience an improvement in<unk>  symptoms when GERD is treated. Other causes of laryngeal hyperresponsiveness include inhalation of toxins and irritants, cold and dry air, episodic croup and laryngopharyngeal reflux (LPR).
Vocal cord dysfunction
Vocal cord paresis
Velopharyngeal insufficiency
Laryngotracheal stenosis
Pulmonary hypoplasia
Tracheomalacia
Congenital limb deformities
Tracheal agenesis