Chronic Cough

Cough is an important defense mechanism, which can be both involuntary and voluntary. The cough reflex is a complicated mechanism involving multiple reflex pathways between the respiratory tract and the brain. Depending on duration, cough can be classified as acute, subacute, or chronic.

Chronic cough is a persistent cough of more than eight weeks and can range from throat clearing to a debilitating cough. Chronic cough affects 10 to 20 percent of adults and there are an estimated 29 million visits to physicians each year for cough. Chronic cough often triggers anger, frustration, disruptive sleep, repeated doctor visits, depression, and urinary incontinence. Another consequence of chronic cough can be social isolation. Patients frequently report that coughing and constant throat clearing interferes with personal and professional relationships and comfort in social situations. Some coughers or throat clearers are unaware of their impact on those around them until a spouse, family member or colleague refers them for help.

Many chronic coughs are caused by multiple causes rather than a single cause. In non-smokers, with a normal chest x-ray, the most common causes of chronic cough include:

• Asthma
• Postnasal drip
• Gastro-esophageal reflux disease (GERD)
• Angiotensin-converting enzyme (ACE) inhibitors