According to primary care physicians, patients typically will not schedule an office visit for flu or upper respiratory infection until their coughing becomes unbearable. Patients can manage sinus congestion, body aches, fever and chills, but persistent cough quickly becomes painful and dangerous, inspiring patients to seek their physicians’ assistance.

Cough Basics: Like Popping a Paper Bag

In general, the body’s cough reflex protects lungs against all impediments to proper breathing. The cough works to dislodge foreign substances from the lungs and airways, and the body’s cough reflex kicks-in whenever nerves called “cough receptors” detect anything foreign. Your esophagus has cough structures in case of trapped food or liquid, and your diaphragm and stomach have cough receptors, too.

The physics of the cough mechanism very closely resemble blowing-up and then popping a paper bag. Elegant in its simplicity, an ordinary cough releases approximately the same force as a category 3 hurricane. Coughing and sneezing rank among the most violent stresses you can put on your body. When the cough receptors detect smoke, vapors, fumes, allergens, bacteria, viruses, mucous, or any other irritant, they signal the brain which in turn signals respiratory muscles. By reflex, you inhale deeply as your glottis closes tight; the glottis is the little gate-like structure in your throat which controls air’s passage in and out of your body. Pressure builds-up in the closed system until the glottis opens as the respiratory muscles contract—like popping the paper bag.

Chronic Cough Signals a Need for Medical Intervention

A persistent cough officially becomes chronic when it lasts more than three weeks. After three weeks, a persistent cough may have taken a heavy toll on a patient’s throat, back and shoulder muscles, stomach muscles and veins. In extreme cases, a chronic cough may cause headache, dizziness, and the sensation of “seeing stars.” A cough also can trigger urinary incontinence, and in the most extreme cases deep and repeated coughs have fractured patients’ ribs. Most importantly, a chronic cough typically represents a warning: some serious respiratory impairment demands intervention and treatment.

Environmental Contaminants Often Cause Chronic Cough

Naturally, doctors differentiate between smokers and non-smokers, following slightly different diagnostic protocols and looking for different kinds of salient symptoms. An alert physician also remains on the lookout for one other key variable—some chronic coughs develop as a result of sustained exposure to dangerous particulate matter in the workplace. Plumbers, pipefitters, and electricians often develop mesothelioma as a result of long-term exposure to asbestos. Carpenters, ironworkers, and concrete finishers often develop a similar respiratory condition called “silicosis,” which results from protracted exposure to silica crystals in the materials they use. Auto-builders also may develop serious respiratory complaints as a result of breathing-in volatile organic compounds—all the toxic chemicals which contribute to the distinctive “new car smell.”

Chronic Obstructive Pulmonary Disease (COPD)

Among smokers who present with chronic coughs, doctors most commonly find toxins from cigarette smoke have compromised their airways, triggering emphysema, chronic bronchitis, or both. Airways become both obstructed and inflamed, so that breathing becomes labored, shallow, and often unproductive. Severe episodes of COPD may reduce a patient’s oxygen intake to only 10% of what the brain and vital organs need to maintain proper function. Naturally, because mucous blocks the patient’s constricted airways, chronic and frequent cough develops, often making regular breathing even more difficult. New medications effectively control COPD in most patients, and respiratory therapists have developed deep-breathing exercises and moderate exercise programs, so that patients can control their symptoms.

Almost all COPD patients suffer periodic “exacerbations”—literally, “irritation and aggravation.” Their symptoms become markedly worse and do not respond to routine treatments. Because breathing difficulties compromise COPD patients’ defenses against infection, they are considerably more susceptible to colds and flu than their age-group peers. Bacteria and viruses most frequently cause exacerbations of COPD; but even something as apparently harmless as a deep breath of cold air may trigger an episode. Severe, relentless coughing often signals the outbreak of an episode, and respiratory therapists recommend COPD patients keep rescue inhalers and emergency oxygen on hand to relieve their symptoms and protect against complications.

Chronic Cough Often Develops with Asthma

Like COPD, asthma symptoms include both airway constriction and inflammation. Patients feel airway constriction, because it results from respiratory muscles’ contracting around airways. This constriction accounts for patients’ presenting with symptoms they describe as “choking, struggling for breath” or “the feeling of being strangled.” Patients may not feel concomitant airway swelling or inflammation. Typically, environmental toxins or allergens trigger asthmatic “attacks.” And, for asthmatics, the “common” cold requires uncommon intervention, because an untreated bacterial or viral infection easily may trigger a severe asthmatic attack. Unlike other serious respiratory complaints, however, asthma has a psychological and emotional component: Especially in children under twelve, stress, anxiety, and trauma induce the most serious asthmatic attacks, and some studies indicate that up to 90% of juvenile asthma is psychosomatic.

The Most Common Causes of Chronic Cough

As flu viruses grow more virulent and drug-resistant, their symptoms persist longer. Even after the most painful flu symptoms have passed, fever has abated and most sinus congestion has eased, post-nasal drip often continues, causing persistent cough that hangs-on for more than three weeks. In extreme cases, physicians will prescribe nasal steroid sprays in combination with strong decongestants to relieve patients’ “annoying tickle” at the backs of their throats. The same applies to serious “hayfever” sufferers, for whom histamine blockers and strong nasal sprays usually bring quick and long-lasting relief.

Somewhat surprisingly, gastro-esophageal reflux disease, more commonly known simply as “acid reflux” often causes chronic cough as strong digestive acids irritate the backs of patients’ throats or get trapped by the epiglottis and trigger the cough reflex. In fact, acid reflux ranks as the third leading cause of chronic cough; and, in more than 40% of cases, patients do not complain of digestive discomfort. The chronic cough is their only symptom.

Common Treatments for Chronic Cough

Physicians naturally prefer to treat causes instead of symptoms. Therefore, when a patient presents with chronic cough, a physician almost inevitably will order a chest x-ray and a sinus x-ray or computed tomography (CT scan). If a patient complains also of breathing difficulties, a physician typically will administer a series of bronchial function tests, often including assessment of how well a patient’s respiration is oxygenating his or her blood. In most cases, physicians will prescribe medications to treat the cough’s causes rather than the cough itself, because they recognize a productive cough’s value in eliminating mucous and congestion from the patient’s lungs.

In cases where persistent cough has caused collateral damage, a physician will prescribe a cough suppressant—usually dextromethorphan, an affine of morphine but without the narcotic effects.