A cough is one of the most common symptoms seen in people of all ages. Just like flu, any changes in the temperature or weather makes you more prone to a cough. But what most of us are not aware of is the fact that it acts as a crucial natural defense mechanism of the respiratory system and maintains airway function by removing excessive secretions from the air passages. However, it can act as a warning sign of various respiratory and non-respiratory conditions including cancer. Here’s more on the types of cough and the most common causes of a chronic cough.
Types of Cough
A cough is broadly classified into an acute or a short-term cough and chronic or a long-term cough.
An acute or short-term cough often occurs in association with an upper respiratory tract infection. It is usually self-limiting and resolves within two-three weeks.
A chronic or long-term cough, also known as a persistent cough, could cause various conditions such as exhaustion, lack of sleep, urinary incontinence, or respiratory illnesses. As a cough can be a sign of numerous health problems, it becomes difficult to diagnose and manage the condition. It usually lasts for eight weeks or more and generally requires medical attention.
Causes of A Chronic Cough
A 2015 study published in the Journal Lung India[1] has reported that approximately 10-20% of the general population suffers from chronic cough. Most patients with a persistent cough have a dry and minimally productive cough. A dry or non-productive cough is the one that produces no phlegm or mucus whereas a wet cough or productive cough is the one which causes the production of phlegm or mucus. Here are some of the common causes of a chronic cough:
1. Smoking: One of the most common causes of a chronic cough is smoking. The impact of smoking on cough depends on the dose of cigarettes[2], which means the risk and severity of cough is higher in smokers as compared to non-smokers. Patients who quit smoking have reported an improvement in their cough.
So quit smoking! This not only lowers the frequency of coughing but also reduces your risk of various health complications including cancer.
2. Indoor air pollution: In adults and school children, productive cough or chronic nocturnal (occurring during night) dry cough has been associated with particulate matter such as PM10[2]. An increase in the levels of PM10 are related to an increased in the severity of a chronic cough, excess production of sputum, and sore throat in children with or without asthma.
Hence, it is advised to keep your home healthy with simple measures such as ensuring proper ventilation and using an air purifier, which help keep the indoor air pollution under control.
3. Certain medications: Medications such as angiotensin-converting enzyme (ACE) inhibitors which are used to control hypertension can also cause a cough. A cough is typically dry and is associated with a tickling or scratching sensation in the throat. The incidence of ACE an inhibitor-induced cough has been reported to be in the range of 5 to 35% among patients who have been treated with these agents[3].
Do talk to your doctor if you are suffering from hypertension and are using any of these antihypertensive medications. Do not self-medicate or stop taking medications without consulting a doctor.
4. Allergies: Exposure to dust and chemicals at home or occupational triggers can lead to a cough and other symptoms of allergies. It causes an increase in the inflammatory compounds which can also lead to increased cough reflex sensitivity. The allergens include pet hair and room fresheners at home or occupational compounds such as hot pepper dust which can cause sensitization of the airways leading to a chronic cough[2].
Beware of the known allergens at your home and office as it can lead to hypersensitivity and trigger an allergic response. Measures such as buying an air purifier can help you to reduce indoor air pollutants and keep your home clean and healthy, and prevent allergies at home.
5. Gastrointestinal problems: Gastroesophageal reflux disease (GERD) is one of the common extrapulmonary causes of a cough. Around 5-41% of cases have reported that GERD can cause a chronic cough[2]. It could be due to an aspiration of gastric content into the larynx and trachea, part of the respiratory tract or due to a dysfunctional or reduced esophageal clearance which leads to a cough.
It is wise to consult a doctor to know the underlying cause of a cough as a proper diagnosis is essential to treat a condition.
6. Respiratory conditions: A chronic cough is a common association of respiratory diseases such as asthma, bronchitis, chronic obstructive pulmonary disease (COPD) and other lung diseases. In most cases, it is usually associated with the production of phlegm. Moreover, a cough may arise as a consequence of cancer or because of its the treatment. Moreover, the toxic vehicle-derived transition metals and ultrafine particles comprise of PM10, which has been increasingly associated with the inflammatory response in airways and lungs[4].
A cough which occurs due to change in season or increase in pollution levels can aggravate an underlying respiratory condition or can cause a respiratory problem. This is the reason why people with a chronic cough are advised to get a thorough respiratory history to know the exact cause of the symptom and get it treated.
This article is sponsored by Honeywell Air Purifiers.
References:
1. Chronic dry cough: Diagnostic and management approaches. Lung India. 2015;32(1):44-9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4298918/
2. Morice AH, McGarvey L, Pavord I; British Thoracic Society Cough Guideline Group. Recommendations for the management of cough in adults. Thorax. 2006 Sep;61 Suppl 1:i1-24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2080754/
3. Peter V. Dicpinigaitis. Angiotensin-Converting Enzyme Inhibitor-Induced Cough ACCP Evidence-Based Clinical Practice Guidelines. https://journal.chestnet.org/article/S0012-3692(15)52845-6/pdf
4. Demoulin-Alexikova S, Plevkova J, Mazurova L, et al. Impact of Air Pollution on Age and Gender Related Increase in Cough Reflex Sensitivity of Healthy Children in Slovakia. Front Physiol. 2016 Feb 23;7:54. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4763033/
5. Worrall G. Acute cough in adults. Can Fam Physician. 2011 Jan;57(1):48-51. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024161/
6. Sharma S, Alhajjaj MS. Cough. Treasure Island (FL): StatPearls Publishing; 2018 Jan. https://www.ncbi.nlm.nih.gov/books/NBK493221/
7. Faruqi S, Murdoch RD, Allum F, Morice AH. On the definition of chronic cough and current treatment pathways: an international qualitative study. Cough. 2014 May 29;10:5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4088926/