Why do I not cough during the day but start coughing when lying down?

Coughing that occurs only when lying down, but not during the day, may be caused by several factors, such as postnasal drip, gastroesophageal reflux disease (GERD), or bronchial spasms. The specific causes are analyzed below:

1. Postnasal Drip

When lying down, secretions from the nasal passages and throat may drain backward and irritate the throat, triggering coughing. This can be associated with conditions such as sinusitis, nasal congestion, or rhinitis. Patients may use saline solution for nasal irrigation, followed by intranasal corticosteroid sprays to reduce inflammation, swelling, and mucus production.

2. Gastroesophageal Reflux Disease (GERD)

GERD is an inflammatory condition caused by stomach acid flowing back into the esophagus, which may irritate the throat and airways and lead to coughing—especially when lying down, as this position can worsen acid reflux. Patients should follow medical advice to take medications such as omeprazole, esomeprazole, or rabeprazole.

3. Bronchial Spasms

In some cases, lying down may trigger bronchoconstriction and spasms, resulting in coughing. This may be related to respiratory conditions such as asthma or chronic obstructive pulmonary disease (COPD). Medications such as theophylline sustained-release tablets, aminophylline, or ipratropium bromide may be taken under a doctor’s guidance.

In addition, cardiac-related cough should also be considered. If this symptom frequently occurs and significantly affects quality of life, it is recommended to consult a physician for a thorough evaluation and diagnosis, and to receive professional medical advice and treatment.