IMPORTANT The information provided is of a general nature and should not be used as a substitute for professional advice. If you think you may suffer from an allergic or other disease that requires attention, you should discuss it with your family doctor. The content of the information articles and all illustrations on this website remains the intellectual property of Dr Raymond Mullins and cannot be reproduced without written permission.

Common cause of short-lived cough

The most common trigger is a respiratory infection and usually settles within a few weeks. Sometimes cough will persist for several weeks, so-called post-infectious cough.

Other cause of cough

• Infection

• Post-infectious cough (whooping cough is a special form of post-infectious cough)

• Post-nasal drip (due to allergy, infection of thick mucus)

• Asthma cough (typically worse with cold air, laughing and exercise, better with asthma puffers)

• Some blood pressure tablets (ACE inhibitors, such as captropril, enaopril, ramipril)

• Heart failure

• Silent acid reflux from the stomach

• Other lung disease (eg. TB, sarcoid, lung fibrosis, chronic lung infection like bronchiectasis, smoking, chronic bronchitis)

• Habit cough and clearance of the throat

• Unknown cause

• “Cough hypersensitivity syndrome”, thought to be due to overactive nerve receptors in the throat

Sometimes testing is needed

Test can be undertaken to prove or disprove disease. For example:

• Allergy testing is hay fever or asthma is suspected to be a cause

• Xrays of chest or sinuses

• Cultures of mucus/sputum to detect infection

• Lung function testing including asthma testing

• Having a direct look at the throat or vocal cords or lungs (laryngoscopy, bronchoscopy)

“Red flags” when cough should be worried about even more

• Coughing up blood

• Smoker with new onset cough or changes in voice

• Cough with shortness of breath

• Fever, weight loss

• Recurrent pneumonia

• Husky voice

Treatment of ongoing/chronic cough

If the cause of cough is obvious, then sometimes treatment is straightforward. In others, one can undertake trials of therapy, such as nasal steroid sprays or antihistamines if hay fever suspected, asthma relievers and preventers if asthma is suspected, changing blood pressure tablets or trialling tablets to suppress stomach acid production and thus acid reflux. In some individuals, however, a cause is not found and may are considered to over overly sensitive upper airways, where talking, exercise or smells can all aggravate cough. When trials of therapy are undertaken, one has to be patient as it may take 4-6 weeks before improvement is seen, especially as the act of coughing sometimes irritates the throat, which perpetuates the irritation that drives the cough. Maintaining adequate water intake is important as dehydration can irritate the throat, dry out mucus and help perpetuate a throat clearance-cough cycle.

Other treatments for chronic cough

There are a range of treatments for chronic cough that may be tried including regular honey or vocal relaxation exercises (especially important in those with habit throat clearance). The aim is to help individual recognise triggers for throat irritation and coughing and substitute another activity such as swallowing or a breathing exercise to reduce throat irritation. A range of other medicines (puffers and tablets) have also been trailed in various studies with a variable degree of success

References

1: Gibson P, Wang G, McGarvey L, Vertigan AE, Altman KW, Birring SS; CHEST

Expert Cough Panel. Treatment of Unexplained Chronic Cough: CHEST Guideline and

Expert Panel Report. Chest. 2016 Jan;149(1):27-44. doi: 10.1378/chest.15-1496.

2: Michaudet C, Malaty J. Chronic Cough: Evaluation and Management. Am Fam

Physician. 2017 Nov 1;96(9):575-580.

3: Gibson PG, Vertigan AE. Management of chronic refractory cough. BMJ. 2015 Dec

14;351:h5590. doi: 10.1136/bmj.h5590.

4: Speich B, Thomer A, Aghlmandi S, Ewald H, Zeller A, Hemkens LG. Treatments

for subacute cough in primary care: systematic review and meta-analyses of

randomised clinical trials. Br J Gen Pract. 2018 Oct;68(675):e694-e702. doi:

10.3399/bjgp18X698885.

Last reviewed 9 June 2020

Introduction

Ongoing cough may affect up to 10% of the population, and can result in significant sleep disturbance and impact on quality of life. Unfortunately, cough I a symptoms that may arise from many causes and some people may have more than one factor playing a role to perpetuate the cough cycle.