Coughing at 4 or 5 a.m. may be due to a respiratory infection or asthma.
1. Respiratory system infection: after the respiratory system infection, there will be a local lesion foci, resulting in increased mucus secretion, the lumen is blocked, the ciliated epithelium on the bronchial tubes cilia swing, which induces cough.
2. Asthma: after the emergence of nighttime asthma will lead to bronchial smooth muscle spasm, short time bronchial tube by the increase in stimulation, strong stimulation will lead to bronchial smooth muscle contraction, thus triggering cough.
Coughing at 4:00 or 5:00 in the morning may also have other causes, such as cardiogenic asthma, allergic cough, etc., should be timely medical care, after a clear diagnosis, give targeted treatment.