Q: I've had a persistent cough for more than two months. The cough is worse after eating and at night when I lie down. I had a chest X-ray, which was normal. What might cause a persistent cough? I've never been a smoker.


I suspect your doctor asked you about related symptoms, such as nasal congestion, wheezing or heartburn. You probably said "no" to these symptoms.


Based on your symptoms of increased cough after eating and at bedtime, esophageal reflux would be at the top of my list. Acid from the stomach can wash back into the esophagus. It then tends to move up higher to the throat. This irritates the tissue and prompts coughing.

Many people with reflux will not experience heartburn or indigestion, and cough may be the only symptom.

Post-nasal drip may not be obvious. Allergies, prolonged congestion after colds and sinus infections are the most common reasons.

Occult asthma means that the wheezing is not obvious and cough may predominate.

Other causes of a prolonged cough include:

--Some medicines (especially ACE inhibitors like captopril, lisinopril, and enalapril)

--Hypersensitive bronchial tubes following an upper respiratory infection

If the cough is secondary to acid reflux:

1. Don't lie down for three hours after eating.

2. Eat smaller meals, especially in the evening.

3. Note which foods make the symptoms worse, and avoid them.

4. Discuss taking an acid blocker with your doctor.

If the persistent cough is due to post-nasal drip, then decongestants and antihistamines should help. For occult asthma, a prescription inhaler could reduce coughing.

