That Nagging Cough

By Michael Lucia, MD

All of us have had that cough that wouldn't go away after a cold or the flu. But when does a cough become more than a viral infection leftover? More than 30 million people every year see their physicians with a chronic cough.Chronic cough (defined as one lasting more than three weeks) is the fifth most common reason for a doctor's visit and one of the most common reasons for referral to a pulmonary specialist. Fortunately, numerous studies have given us answers regarding causes, diagnosis and treatment of the condition.

Many patients are unaware of the most common causes of chronic cough and often pressure their physicians for antibiotics, believing that a persistent infection is the root cause. And while the condition sounds like a mere nuisance, living with a chronic cough can cause serious complications including broken ribs, insomnia,incontinence and even job loss because of the social stigma associated with coughing in public.

Coughing is a complex process involving numerous muscle groups coordinating to protect the lungs from irritants. Multiple triggers for cough are located in the throat, ear, esophagus and lung. Because of the many sources, a variety of disorders can affect or worsen the cough reflex.

Most viral infections, such as the common cold, cause a temporary inflammation of the upper airway that triggers coughing for one to three weeks. Almost all such cases will clear up by treating the symptoms with cough suppressants and lozenges.

A cough that persists longer than three weeks should be evaluated more thoroughly. When a cough persists for months, more serious causes like asthma,gastroesophageal reflux (GERD) or postnasal drip (PND) should be considered.Ninety-five percent of all chronic cough can be treated successfully with a systematic approach.

PND is the most common cause in adults, and can be allergic or nonallergic in nature. The next most likely cause is GERD, followed by adult-onset asthma, and then a combination of two or more of these conditions. All of these underlying conditions are easily identified with diagnostic testing along with patient history and physical exam. Most cases can be treated with excellent results using medications.

A cough that produces bloody sputum, especially in a smoker, should be evaluated right away as this can be a harbinger of much more serious conditions such as cancer or blood clots within the lung. However, blood-streaked phlegm in a nonsmoker is common and usually due to bronchitis or pneumonia.

If a cough begins without an infection, other considerations include many commonly used prescription medications. Blood pressure agents known as ACE inhibitors and beta-blockers both are associated with development of a cough.

So when that winter cold or allergy strikes and the cough begins, follow the old tried-and-true treatments first: lozenges, cough syrups with dextromethorphan (Robitussin) and adequate rest and hydration. Avoid irritants like secondhand smoke and dust. If the cough persists even when the cold has long gone,however, consider seeing your doctor. Many patients live with coughing for months or even years before seeking attention. Don't let that chronic cough become an old friend before getting help.