“Three things cannot be hidden: coughing, poverty and love.” So goes a Yiddish proverb. English poet George Herbert, nestled in between the ages of Shakespeare and Milton, made it shorter: “Love and a cough cannot be hid.”
To us, doctors, cough comes easy. The symptoms of cough like to flaunt themselves. A dry cough, a hacking cough, a productive cough (wet cough that produces mucus or phlegm)… Yet, believe it or not, this extremely common condition can turn fatal if neglected and/or abused. Like any other symptom, cough can be self-limiting, turn progressively worse or become recurrent. A cough syrup or a tablet will suppress the incidence or frequency but not the root cough sprouts from.
This makes it imperative to know the genesis of cough. With that in mind, let’s address some of the common and not-so-common causes of cough.
Asthma
Asthma is a leading cause of persistent cough in adults and the most common cause in children. Cough due to asthma is commonly accompanied by episodic wheezing and dyspnea (shortness of breath). However, it can also be the sole manifestation of a form of asthma called “cough-variant asthma”, which can eventually progress to include wheezing and dyspnea.
Acid reflux
The reported prevalence of cough due to gastroesophageal reflux disorder (GERD) varies widely. Some studies report that GERD is the second or third most common cause of persistent cough. Typically, acid reflux associated cough gets accompanied by nasal symptoms, heartburn, or a sour taste in the mouth.
Post-nasal drip
Upper airway cough syndrome (UACS) is thought to be due to “post-nasal drip” or nasal secretions flowing into the nasopharynx caused by allergic, perennial non-allergic or vasomotor rhinitis or rhinosinusitis. The exact role of UACS as a cause of chronic cough is unclear, although several studies suggest that UACS related to post-nasal drip is a common cause of sub-acute and chronic cough.
Nonasthmatic eosinophilic bronchitis
Nonasthmatic eosinophilic bronchitis (NAEB) is an increasingly recognised cause of chronic non-productive cough, particularly in patients who lack risk factors for other common causes of chronic cough. Patients with NAEB demonstrate atopic (allergic) tendencies, with elevated sputum eosinophils and active airway inflammation.
Acute, sub-acute and chronic cough often overlap TT Archives
Drug-induced cough
Cough is a common complication of several classes of medications, particularly a class of antihypertensives called angiotensin-converting enzyme (ACE) inhibitors. Others implicated are drugs that increase gastroesophageal reflux, such as calcium channel blockers and bisphosphonates (used for osteoporosis), which can theoretically worsen pre-existing reflux and potentially increase cough.
Prolonged post-infectious cough
Cough following viral or other upper respiratory tract infections can persist for more than eight weeks after the acute infection. Such cases increase in frequency during outbreaks of some bacterial and viral infections, including Covid-19.
Lung diseases
While bronchitis and bronchiectasis are manageable to a large extent, despite the suffering, interstitial lung disease and lung cancer are the two particular causes whose effects are debilitating and, invariably, fatal if not apprehended in a timely manner.
I will end on a note of caution. Most books will quantify acute, sub-acute and chronic cough with numbers, with acute being present for three weeks, sub-acute for three to eight weeks, and chronic lasting longer than eight weeks. I remain leery with such quantifications. They are frequently overlapping and misleading. Don’t go just by the numbers. If you are coughing for some time, seek a doctor’s attention. In medicine, time is everything.
Dr Shuvendu Sen, born and brought up in Kolkata, is a US-based physician currently serving as the vice-chair, Research, at the Jersey Shore University Medical Center, New Jersey. An award-winning physician and author, his works include The Fight Against Alzheimer’s (Rupa Publications, 2024), Why Buddha Never Had Alzheimer’s (HCI/ Simon & Schuster, 2017) and A Doctor's Diary (Times Group Books, 2014), among others. Dr Sen can be reached at shuvendusen57@gmail.com
