Conquering a Chronic Cough

You have a tickle in your throat. You start coughing and can't stop. Gulping some water doesn't help. You pop a menthol-flavored cough drop in your mouth. Still coughing. This has been happening for what seems like forever, way longer than two months, and when you finally go to your primary care physician, she nods wisely and says, "Yes, you have a chronic cough."

Thanks for the diagnosis, doc.

Coughing is one of the main symptoms that brings people to the doctor's office, with an estimated 30 million visits annually. Acute coughs, symptoms of the common cold, flu, bronchitis, pneumonia and COVID-19, are part of an infectious process such as a viral or bacterial infection. 

These can be treated with antibiotics (if caused by bacteria), cough suppressants or expectorants, menthol lozenges, drinking plenty of fluids to thin the mucus, and using a vaporizer. And, according to my mother, a steaming, soothing bowl of chicken soup never hurt anyone.

"Coughs caused by viral infections can be very damaging to the nerve endings in the pharynx and trachea and can persist after all the other symptoms of an acute infection are gone," says Ana Zamora-Martinez, M.D., a pulmonologist at the Mayo Clinic in Phoenix, Arizona and Medical Director of the Interstitial Lung Disease Clinic.

Chronic cough, as opposed to acute, is defined as any cough that has lingered for more than eight weeks. Cigarette smoking and occupational and environmental exposure to irritants are known precipitants. While people worry that something is seriously wrong when a cough continues for months, there's usually help for a chronic cough once it's properly diagnosed.

Aye, there's the rub. Depending on the initial exam, your primary doctor may want you to go to a pulmonologist, an allergist, an otolaryngologist (ENT) or a gastroenterologist to get a comprehensive work-up. Depending on which type of doctor you see, diagnostic tests may include laboratory tests, x-rays, CT (computerized tomography) scans, bronchoscopy, rhinolaryngoscopy, endoscopic exams of your esophagus, and pulmonary function tests.

"By the time patients make an appointment with me, they have usually seen at least one other doctor and have not gotten any relief. Because diagnosing chronic cough can be complex, I need to put on my pulmonary detective cap," says Zamora-Martinez.

"Besides doing a variety of diagnostic tests, I will ask questions such as: is there a time of day when the cough is worse, is your cough dry or do you feel like you have mucus in your throat, do you get frequent heartburn, and have you noticed that you cough more in the winter or when there is a change in temperature?"

Chronic coughs can seriously affect quality of life, causing symptoms such as headaches, exhaustion, dizziness, musculoskeletal pain, hoarseness and insomnia. One study of women at a U.S. cough clinic found that 63% reported urinary stress incontinence induced by coughing. Emotional symptoms such as embarrassment, frustration and depression may be present.

Coughing has a protective role in the airways and lungs, helping to clear mucus and other secretions from the airways and prevent aspiration or inhalation of pathogens. Mechanical or inflammatory irritants usually trigger coughs.

"We have cough receptors in the trachea and large and small bronchi, just as you'd expect," says Zamora-Martinez. "However, they are also in the ear canal, the eardrum, the paranasal sinuses, the esophagus, stomach, diaphragm and pericardium."

Impulses from stimulated cough receptors travel a pathway via the vagus nerve to a "cough center" in the medulla area of the brain. This generates a signal that moves down to the diaphragm, chest wall and abdominal muscles to produce a forcible exhalation and cough.

When this process goes awry due to overstimulation or sensitization of the nerve fibers, it can lead to chronic cough, damage to airway tissues and subsequent inflammation.

The longitudinal Rotterdam Study monitored almost 10,000 people over 45 years of age, about 10% of whom had a chronic cough at the beginning of the study, and found that the condition increased with age, peaking in the eighth decade of life. In people under seventy, the chronic cough was more prevalent in women.

Upper airway cough syndrome includes rhinitis and postnasal drip/ sinusitis. These can be caused by allergies (such as hay fever) or by inflammation of the lining of the nose and sinuses. Oral antihistamines for allergic rhinitis and saline rinses followed by a steroid nasal spray are helpful. 

"Bathing the nose with hypertonic saline is a crucial step because antigens, which latch into the hair of the nose, can be washed away," says Zamora-Martinez. Decongestants, if warranted, should only be used for a short period.

Acid reflux (gastroesophageal reflux disease, also known as GERD) occurs when acid from the stomach flows back up into the esophagus, the tube that connects the stomach and the throat. This irritation frequently leads to a chronic cough. Some people with reflux experience heartburn or a sour taste in their mouth, but many have silent GERD with no acid-related symptoms, except perhaps the sensation of food sticking in the throat. 

Treatment consists of proton pump inhibitors (PPIs) and lifestyle changes such as weight loss, smoking cessation, sleeping with the head elevated six to eight inches and avoiding certain foods and beverages that cause reflux.

Cough-variant asthma causes cough but no wheezing and is treated similarly to regular asthma, with inhaled steroids such as Flovent, Pulmicort or an inhaled bronchodilator to open the airways.

ACE inhibitors (angiotensin-converting enzyme inhibitors), used to treat high blood pressure, are known to cause a chronic, dry hacking cough in between 10 and 20% of patients taking them. If the medication is switched to another, the cough usually disappears within one to two weeks.

Neurogenic cough, also known as cough hypersensitivity syndrome or psychogenic cough, is a diagnosis of exclusion. The nerve that provokes the cough reflex has become responsive to very low levels of stimulation. Sensations of throat irritation, an urge to cough, and coughing bouts are therefore triggered by low levels of irritants, physical stimulation of the larynx (talking and eating), and changes in temperature or humidity.

Less common but more serious causes of chronic cough include COPD (chronic obstructive pulmonary disease), bronchiectasis, eosinophilic bronchitis, lung cancer, interstitial lung disease, pulmonary fibrosis and tuberculosis.

Unfortunately, between 5% to 10% of patients have a treatment-resistant, chronic refractory cough, which is idiopathic, meaning no cause can be found. Speech and language therapy is beneficial by teaching cough suppression strategies and increasing the cough threshold. 

According to physician researchers at the Mayo Clinic Cough Clinic, several medications, including amitriptyline, duloxetine, gabapentin and pregabalin, have been studied and clinical trials with P2X3 (receptor antagonists that focus on the cough reflex pathway) are ongoing. Using nerve blocks to interrupt the cough reflex is another treatment being utilized by some physicians.

Excellent information for those living with chronic cough can be found at The Cough Chronicles, an educational resource sponsored by Merck in collaboration with the American Lung Association, the Asthma and Allergy Foundation of America, and the Allergy & Asthma Network. 

You can use their online cough tracker to note potential patterns, sound characteristics and possible triggers and share it with your health care provider.

Barbra Williams Cosentino RN, LCSW, is a psychotherapist in Queens, N.Y., and a freelance writer whose essays and articles on health, parenting and mental health have appeared in the New York Times, Medscape, BabyCenter and many other national and online publications. Read More