A Dry Cough: What It Is and Why It Happens
Coughing is a natural reflex that is characterized by a sudden outward expulsion of air. In principle, its function is to clear the airways. It may also be a symptom or a consequence of underlying respiratory disorders, especially when it persists for several days. We review the causes of a dry cough and everything you need to know about it.
When the dry cough occurs only occasionally, it shouldn’t cause concern. Changes in the outside temperature (very cold or dry weather) could explain it. The opposite happens when it’s a symptom that lasts for days, weeks, and even months. The causes of a dry cough are very varied, and most of the time it’s something that can be controlled.
7 causes of a dry cough
A dry cough is a type of cough that isn’t accompanied by phlegm or mucus (sputum). Contrary to the function that we have pointed out, it’s a non-productive cough. This is because, in the absence of the above, it cannot clear the airways and instead has an irritant effect. A dry cough is characterized by the following:
- Tickling or irritation in the throat
- Pain or discomfort when drinking water or swallowing food
- A permanent tingling sensation
- Changes in the tone of the voice
A dry cough can be a sporadic episode, or last for a week or two. When the symptom extends beyond 8 weeks, it’s said that the person is suffering from a chronic cough.
There are two main scenarios behind the causes of dry cough: it is a remnant of a condition that has been overcome, or, on the contrary, a symptom of a condition that is present at the moment. We leave you with 7 possible explanations for it.
1. Allergic episodes
As the experts point out, many allergic episodes, such as asthma, produce a dry cough. Not all asthma episodes develop with a dry cough, but the truth is that many do. Sometimes the term allergic cough is used to refer to symptoms of this type triggered by coming into contact with an allergen.
For example, dust, dander in animal hair, pollen, latex dust, and so on. It can be accompanied in this sense by other allergy symptoms such as runny nose, teary eyes, hives, episodes of swelling and others. It’s usually a symptom that worsens in the late afternoon and at night when its triggers are allergies.
2. Gastroesophageal reflux disease
Specialists associate some episodes of gastroesophageal reflux disease as catalysts for a dry cough. The condition is characterized by stomach acid leaking into the esophagus.
It is also manifested in non-acid episodes, also in laryngopharyngeal reflux. It isn’t always accompanied by the typical symptoms of the condition, such as burning in the chest, difficulty swallowing, and regurgitation of food.
3. Intake of some medications
Another possible cause of a dry cough is the side effects of taking medication. As the evidence points out, many of them can cause episodes of persistent coughing.
The drugs that usually cause this complication are angiotensin-converting enzyme inhibitors, calcium channel blockers, angiotensin II receptor blockers, fentanyl, sitagliptin, and latanoprost.
4. Viral or bacterial infections
Within this category we can list a wide variety of dry cough catalysts. Viral or bacterial infections in the respiratory tract can cause this symptom, and it can even remain as a remnant for several days after they have passed. We have compiled a list of the main ones:
- A cold
- The flu
- Pneumonia
- Pharyngitis
- Bronchitis
- Laryngitis
- Sinusitis
It’s very normal for a dry cough to appear after getting over a cold or flu. Usually it will last for only a couple of days and then it will go away on its own. The same goes for the other conditions on the list.
5. Exposure to irritants
Specialists agree that exposure to certain environmental agents can be the cause of a dry cough.
Among the most significant are cigarette smoke (actively or passively), dust from construction sites, environmental contamination, factory waste, interaction with chemicals, and gases as a by-product. Those who are exposed to some of these in an occupational setting are at increased risk of developing it.
6. Sleep apnea
Sleep apnea has been linked to episodes of chronic dry cough. In fact, it is estimated that up to 40% of people with sleep apnea develop a dry cough as a complementary symptom.
The relationship isn’t well understood, but inflammatory processes as a consequence of snoring may be behind it. Since many of the patients experience reflux symptoms at night, the trigger can also be found in it.
7. Upper respiratory cough syndrome
Also known as postnasal drip syndrome, this is a dripping down the back of the throat that occurs from excess mucus in the nose or sinuses.
Evidence indicates that one of its characteristic symptoms is a dry cough. This can be the catalyst for chronic episodes – episodes that last for more than two months.
In the company of all these causes of dry cough, we can’t fail to mention cough hypersensitivity syndrome. Although it’s a clinical entity that can be rather controversial, experts use it to refer to people who show greater sensitivity to internal and external agents that cause the cough reflex.
We would like to remind you that the explanations given are only referential. If you have a persistent dry cough, don’t hesitate to seek medical assistance. It’s likely to require treatment, so the sooner you act, the better for your health.
- Birring SS, Ing AJ, Chan K, Cossa G, Matos S, Morgan MD, Pavord ID. Obstructive sleep apnoea: a cause of chronic cough. Cough. 2007 Jul 2;3:7.
- Jo EJ, Song WJ. Environmental triggers for chronic cough. Asia Pac Allergy. 2019 Apr 20;9(2):e16.
- Lucanska M, Hajtman A, Calkovsky V, Kunc P, Pecova R. Upper Airway Cough Syndrome in Pathogenesis of Chronic Cough. Physiol Res. 2020 Mar 27;69(Suppl 1):S35-S42.
- Li X, Lin S, Wang Z, Zhang H, Sun X, Li J, Wu D, Ke M, Fang X. Gastroesophageal reflux disease and chronic cough: A possible mechanism elucidated by ambulatory pH-impedance-pressure monitoring. Neurogastroenterol Motil. 2019 Dec;31(12):e13707.
- Mahashur A. Chronic dry cough: Diagnostic and management approaches. Lung India. 2015 Jan-Feb;32(1):44-9.
- Song WJ, Morice AH. Cough Hypersensitivity Syndrome: A Few More Steps Forward. Allergy Asthma Immunol Res. 2017 Sep;9(5):394-402.
- Shim JS, Song WJ, Morice AH. Drug-Induced Cough. Physiol Res. 2020 Mar 27;69(Suppl 1):S81-S92.
- Wang TY, Lo YL, Liu WT, Lin SM, Lin TY, Kuo CH, Chung FT, Chou PC, Chang PJ, Ni YL, Ho SC, Lin HC, Wang CH, Yu CT, Kuo HP. Chronic cough and obstructive sleep apnoea in a sleep laboratory-based pulmonary practice. Cough. 2013 Nov 5;9(1):24.
