Elderly people who do not cough during the day and cough uninterruptedly at night may be caused by cough variant asthma, cardiac insufficiency, allergies and so on. 1. Cough variant asthma, paroxysmal cough at night is its typical symptom, due to the vagus nerve excitation can produce night cough aggravation performance. 2. Cardiac insufficiency, after lying down, the cardiac reflux increases significantly, but the heart can not bear the higher intensity, it may cause circulatory disorders, the formation of cough performance, is also one of the common reasons. 3. Allergy, may be allergic to bed mites and other substances, resulting in allergic cough, the need for timely allergen screening to clarify. Elderly people do not cough during the day, there are many other reasons for uninterrupted coughing at night, it is recommended to seek medical advice in a timely manner, under the guidance of the doctor to carry out the relevant examination, and treatment in accordance with medical advice.