Nocturnal asthma is a term used to describe the condition of asthma patients whose symptoms strike mostly at night – most often while the patient is sleeping. Nocturnal asthma includes chest tightness, shortness of breath, cough, and wheezing, and these symptoms can make sleep almost impossible, allowing the patient very little rest, leading to fatigue, irritability and sleepiness in the daytime.

While sleeping, the bronchioles in the lungs become narrower, which may result in increased an increased resistance of the airflow. This in turn may trigger frequent nighttime coughing resulting in a further tightening of airways. For people with asthma, the number of inflammatory cells in the airways is highest in the early morning, with a peak at 4 AM.

Most people who have asthma also have sinusitis, so increased drainage from the sinuses can also trigger asthma in highly sensitive airways. Lying in the reclining position might contribute to the problem as well. The building up of secretions inside the airways is one reason, but other contributing factors such as heightened blood volume inside the lungs; reduced overall lung volume, and increased resistance in the airway may also trigger nocturnal asthma.

Treatment for nocturnal asthma is similar to any other asthma treatment. Long acting steroid inhalers help a great deal, as they can last throughout the night.