Common Causes Of Cough

The three most common causes of chronic cough (cough lasting longer than 8 weeks) are:
A) Postnasal drip, asthma, GERD.
B) GERD, COPD, congenital lung disease.
C) Lung cancer, postnasal drip, COPD.
D) Obstructive sleep apnea, respiratory infections, asthma.

Answer And Discussion

The correct answer is “A.” Postnasal drip, asthma, GERD.

Epidemiologic studies have demonstrated that most cases of chronic cough are due to postnasal drainage, asthma, or Symptomatic GERD. Most cases of chronic cough seem to have only a single cause, although some will have more than one cause. Empiric therapy should be aimed at these top three causes. Of course, infection (pertussis in particular), malignancy, and other causes
of cough are important to consider—and potentially rule out—as well.
The evaluation of chronic cough should proceed in a logical manner. Usually, history and physical
exam will find the cause. If this is unrevealing, consider a stepwise evaluation including addressing each of the etiologies (given below) in a serial fashion. If this still does not give you an answer, consider a methacholine challenge test to see if you can reproduce the symptoms that would lead you to a presumptive diagnosis of asthma with normal spirometry.

 SELECTED COMMON CAUSES OF ACUTE AND CHRONIC COUGH

Acute :

• URI, 
• pertussis, 
• allergic rhinitis, 
• COPD exacerbation, 
• asthma, 
• acute sinusitis

Chronic:

• GERD, 
• postnasal drip, 
• asthma, 
• chronic sinusitis, 
• allergic/vasomotor rhinitis, 
• ACE inhibitors, 
• eosinophilic bronchitis, 
• chronic bronchitis,