Cough
What is Cough ?
It’s a reflex causing the powerful release of air from the lungs. This clears the airways of mucus and irritants like dust. It often signals respiratory disease, but can also result from issues beyond the lung. Cough can be a cause of concern.
What causes cough?
It can be short-lived (acute), lasting less than 8 weeks or persistent (chronic) lasting 8 weeks or more.
Causes of short-lived cough:
- Upper respiratory tract infection
- Lower respiratory tract (chest) infection
- Allergic inflammation of the upper airways and sinuses (allergic rhinosinositis)
- Exacerbation (flare-up) of underlying chronic respiratory disease (e.g. asthma, COPD, interstitial lung disease)
- Inhalation of irritants (e.g. dust or smoke)
Causes of a persistent cough:
- Rhinosinusitis (post-nasal drip)
- Gastro-oesophageal reflux disease (heartburn)
- Laryngopharangeal reflux
- Asthma
- Medication (e.g. angiotensin converting enzyme inhibitors for high blood pressure)
- Other lung pathology (e.g. lung cancer, respiratory infection, bronchiectasis, COPD, interstitial lung disease)
- Cough hypersensitivity syndrome
Associated symptoms
- Fevers
- Night sweats
- Weight loss
- Coughing blood
- Green mucus / phlegm
- Noisy breathing
- Shortness of breath
- Difficulty swallowing
- Chest pain
Diagnosis
The history often has clues to the cause of a cough. However, investigations may be needed to exclude or confirm certain conditions.
Often a chest x-ray and lung function tests are performed. Investigations, such as sputum cultures, allergy testing, video fluoroscopy, echocardiogram, ambulatory pH studies, bronchial provocation tests, CT chest scans, or CT sinus scans may be performed if needed.
How is cough treated?
Short-lived cough often doesn’t require specific treatment and resolves on its own. Home remedies containing honey and lemon may help.
Often the cause is multi-factorial and combination treatments are needed.
Management is focused at treating the underlying condition:
- Infections are treated with antibiotics or anti-fungals
- Rhinosinusitis may need treatment with anti-inflammatory medication (e.g. intranasal steroids and anti-histamines), antimicrobials or nasal decongestants depending on the cause
- Gastro-oesophageal reflux may need treatment with acid suppressing medication
- Asthma can be treated with inhaled corticosteroids
- Medication related cough is treated by stopping the offending medication
In 10-20% of cases, the cough’s cause remains unidentified or is resistant to treatment. This is frequently linked to cough hypersensitivity syndrome. Techniques to suppress the cough and lessen laryngeal muscle tension prove beneficial. Sometimes, medications that alter the nervous system (e.g., amitriptyline, pregabalin, or gabapentin) or drugs that inhibit the cough reflex (e.g., opiates) are employed.
Other things that may help:
- Quitting smoking, if you smoke, is also likely to help.
- Keeping the throat well hydrated – drinking frequent sips of water
- Breathing in through the nose and out through the mouth