Nocturnal Asthma
Patients with nocturnal asthma often present with repetitive arousals and awakenings during the night accompanied by complaints of breathlessness, coughing, and wheezing secondary to bronchocontriction.25 A variety of factors may contribute to the worsening bronchoreactivity that occurs during sleep, including a relative increase in parasympathetic tone and decrease in nonadrenergic, noncholinergic discharge; comorbid gastroesophageal reflux or obstructive sleep apnea; circadian changes in levels of endogenous hormones (eg, catecholamines, cortisol, or histamine); or reduction of lung volumes and airway size. If severe, nocturnal asthma may give rise to significant hypoxemia.
Source : Respiratory Disorders and Sleep, An Issue of Sleep Medicine Clinics (The Clinics: Internal Medicine)
