Colds with a strong cough at night may be caused by nocturnal vagus nerve excitation, cold air stimulation at night, dry indoor air and other reasons. 1. Nighttime vagus nerve excitation: Colds are caused by viral infections, and symptoms such as nasal congestion, runny nose and cough will occur. At night, due to increased vagus nerve excitability, causing bronchial smooth muscle spasm, increased secretion, stimulation of the airway leading to coughing, it will be manifested in the night cough obvious. 2. Cold air stimulation at night: airway sensitivity increases when you have a cold, and at night, because of the large temperature difference, the cold air can stimulate the airway, which can easily cause a strong cough at night. 3. Dry indoor air: When you sleep, especially if you breathe with your mouth open, the dry air will pass through your mouth and directly into the respiratory tract, thus causing dryness of the mucous membrane of the respiratory tract and a strong cough at night. If the cold suddenly worsens, you need to be vigilant for complications such as trachea-bronchitis and pneumonia. Secondly, coughing at night is not always caused by colds, but may also be caused by other diseases, such as cough variant asthma. If the symptoms are severe or do not improve, you should consult a doctor to determine the cause of the illness and follow the doctor’s instructions for medication, so as to avoid delaying the condition.