Cough That Won't Go Away in Australia: When It's More Than a Cold
Coughs are normal during and after most respiratory infections. They become medically interesting when they outlast the illness that caused them.
The three time-based categories
- Acute cough: less than three weeks. Usually viral, expected to resolve.
- Subacute cough: three to eight weeks. Often a post-viral cough that's lingering longer than expected. Sometimes worth a GP review.
- Chronic cough: more than eight weeks. Always worth investigation. A chronic cough is rarely just a stubborn cold.
The most useful threshold is three weeks. That's the point at which Australian clinical guidance recommends a closer look (Lung Foundation Australia, RACGP, 2024). Before three weeks, watch and wait is usually appropriate in an otherwise well person without red flags. After three weeks, a GP can start working through the most common causes.
The honest answer to "is this normal" is usually yes, in the short term. About a quarter of adults will still have a cough at three weeks after a viral chest infection. By six weeks, most have cleared. By eight weeks, a cough that's still around is no longer post-viral and deserves to be looked at properly.
If your cough has been hanging on, you can book a telehealth appointment with an Abby Health GP to talk through what's going on and what tests, if any, are worth doing.
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It surprises most people that the cough often outlasts the cold by weeks. There's a reason.
Airway inflammation persists
Even after the virus has cleared, the lining of the airways stays irritated. Microscopically, the cilia (the tiny hair-like structures that move mucus out of the lungs) have been damaged and take time to recover. Until they do, mucus clearance is impaired and the cough reflex stays sensitive. This is what we call a post-viral cough, and it accounts for the majority of subacute coughs.
Post-nasal drip continues
The nose and sinuses can keep producing mucus that drips into the back of the throat for weeks after the head cold has gone. The body coughs to clear it. This is one of the most common causes of a cough that won't quit.
The cough reflex itself becomes hypersensitive
After a respiratory illness, the nerve endings in the airways stay extra responsive to triggers like cold air, talking, and exercise. The result: a dry, sometimes tickly cough that fires off at slight provocations.
Something else has been triggered
Sometimes a viral illness uncovers or worsens an underlying condition that was sitting quietly, such as asthma or reflux. The cold goes; the cough stays because the underlying condition is still doing its thing.
Most post-viral coughs settle within four to eight weeks without specific treatment. The job at this stage is to rule out anything serious, treat any contributing factors (post-nasal drip, asthma, reflux), and let time do the rest.
Once a cough is more than three weeks old in an otherwise well person, there are five common causes that account for most cases. Australian clinical guidance frames the workup around these (RACGP, Lung Foundation Australia, Asthma Australia).
1. Post-viral cough
The most common cause of a subacute cough. Follows a recent cold, flu, or other respiratory infection. Typically dry, sometimes with intermittent mucus. Improves over weeks. No specific treatment needed in most cases.
2. Post-nasal drip (upper airway cough syndrome)
Mucus from the nose and sinuses dripping down the back of the throat triggers coughing. Often worse in the morning and on lying down. Hay fever, sinusitis, and chronic rhinitis are common drivers. Treatable with nasal sprays, antihistamines, and managing the underlying allergies.
3. Cough-variant asthma
Asthma can present as cough alone, without obvious wheeze or breathlessness. Often worse at night, with exercise, or with cold air. A GP can arrange spirometry and a trial of an inhaler if asthma is suspected.
4. Gastro-oesophageal reflux (GERD)
Stomach acid travelling up the oesophagus can irritate the airways and cause a chronic cough, sometimes without obvious heartburn. Lifestyle measures and acid-suppressing medication of the proton pump inhibitor class are the usual treatment approaches.
5. Medication-induced cough
A class of blood pressure medications called ACE inhibitors causes a dry, persistent cough in around 10 percent of users. A GP can switch to an alternative if needed.
Less common but important causes
- Whooping cough (pertussis), which can present in adults as a prolonged cough with paroxysms.
- Tuberculosis, particularly in people from or visiting higher-prevalence countries, or those immunocompromised.
- Lung cancer, particularly in current or former smokers, or with a new cough plus weight loss, coughing up blood, or breathlessness.
- Heart failure, which can cause cough alongside breathlessness and ankle swelling.
- Bronchiectasis, where the airways are abnormally widened and produce daily mucus.
Most long coughs are not serious. The handful of presentations in this list always warrant prompt review. They are worth knowing because the small risk of a serious cause is meaningfully reduced by early investigation.
See a GP urgently (within days) if:
- You're coughing up blood, even small amounts. This always needs assessment.
- You've noticed unexplained weight loss alongside the cough.
- You're more breathless than usual, particularly at rest or on light activity.
- You have night sweats that drench your bedding.
- You have a persistent unexplained fever.
- The cough has changed in character recently in a current or former smoker. New persistent cough in this group warrants prompt review.
- You have a known underlying lung condition (asthma, COPD, bronchiectasis) and your cough or symptoms have changed.
- You're immunocompromised (chemotherapy, organ transplant, HIV, certain medications).
- You've recently travelled from a country with higher rates of tuberculosis, particularly if cough is combined with night sweats, weight loss, or fever.
Call 000 or go to an emergency department for:
- Severe shortness of breath at rest.
- Coughing up large amounts of blood.
- Sharp chest pain that's severe or radiates to the arm, jaw, or back.
- Lips or fingertips turning blue.
- Confusion, fainting, or severe weakness.
If you're unsure, Healthdirect on 1800 022 222 is a free 24-hour nurse triage line that can advise.
A GP works methodically through the most likely causes, ruling them in or out based on history, examination, and tests where needed.
The history (the most important part)
- How long has the cough been there? When did it start?
- Did it start after a cold or other infection?
- Is it dry or productive? What does the mucus look like?
- What time of day or night is it worst?
- What makes it better or worse? Exercise, cold air, lying down, eating?
- Any heartburn, reflux, or worse symptoms after meals?
- Any blocked nose, runny nose, or post-nasal drip sensation?
- Any breathlessness, wheeze, or chest tightness?
- Smoking history, past and present.
- Medications, especially blood pressure medications and recent antibiotics.
- Travel history, exposure to tuberculosis, occupational exposures.
- Any of the red flags from the previous section.
The examination
- Listening to the chest with a stethoscope.
- Looking in the nose and throat for evidence of post-nasal drip.
- Checking lymph nodes, oxygen levels, and general appearance.
Tests considered
- Spirometry, the breathing test, if asthma or COPD is on the list. Done in person at a clinic or pathology centre.
- Chest X-ray, if a structural cause or pneumonia is plausible.
- Blood tests, particularly a full blood count and inflammatory markers, if a broader workup makes sense.
- Allergy testing if hay fever or chronic rhinitis seem to be contributing.
- Referral to a respiratory specialist if the cause remains unclear after standard workup.
Most coughs are explained within one or two consultations. The unusual case is when the cause remains elusive after standard workup, which is when specialist input helps.
Online appointments for a lingering cough
Abby Health is an Australian online-first clinic with GPs available seven days a week. For a cough that won't quit, telehealth fits the typical workup well: history is the most important part of working out the cause, and history can be taken thoroughly over video.
- A consultation with an Australian GP who walks through the cough history, asks the questions that distinguish the common causes, and identifies any red flags.
- Pathology requests emailed to you for any blood tests or other investigations needed. Attend your nearest Medicare-eligible collection centre at your convenience.
- Referrals for chest imaging or spirometry when clinically indicated. These tests are done in person at a clinic or radiology centre; Abby helps coordinate.
- Prescriptions when appropriate. Reflux treatment, inhalers for asthma, nasal sprays for post-nasal drip. See online prescriptions.
- Medical certificates issued during the consultation if you need time off work or study.
- Follow-up review with the same care network, so you don't repeat your history each time.
- Specialist referrals when the cause is unclear after standard workup or when a respiratory physician's opinion is needed.
What telehealth can't do is replace an in-person examination if one is clinically required. For listening to the chest in detail, on-the-spot pulse oximetry, or hands-on examination, an in-person review is needed. Abby's GPs make that call openly and help direct you to the right setting.
Abby Health is bulk billed for eligible patients with a valid Medicare card. Strict eligibility criteria apply.
How long should a cough last after a cold?
Most cold-related coughs settle within two to three weeks. About one in four adults still has some cough at three weeks. By eight weeks, almost all post-viral coughs have cleared. A cough beyond eight weeks deserves investigation.
When should I worry about a long cough?
Worry threshold is lower if you're coughing up blood, losing weight unexpectedly, are short of breath, have night sweats or persistent fever, are a current or former smoker with a new cough, are immunocompromised, or have a known lung condition. In any of those cases, see a GP within days.
Can stress cause a chronic cough?
A psychogenic or habit cough does exist but is a diagnosis made after ruling out other causes. Don't accept stress as the explanation until the standard workup is complete.
Should I keep taking over-the-counter cough syrups?
Evidence for the effectiveness of most over-the-counter cough mixtures is limited, particularly in adults. Honey works as well as many syrups for cough in anyone over 12 months. If a cough is bad enough to need medication, it's worth a GP review rather than continued self-treatment.
Why does my cough come back every night?
Nocturnal cough is classic for two causes: post-nasal drip (mucus pools at the back of the throat when lying down) and asthma (airways narrow more at night). Reflux can also worsen lying down. A GP can work out which is most likely.
Do I need a chest X-ray?
Not every long cough needs imaging. The GP decides based on the clinical picture: a chest X-ray is more often arranged for current or former smokers, anyone with red flags, or coughs that have lasted more than eight weeks without explanation.
Can I get a referral to a specialist over telehealth?
Yes. If a respiratory specialist's opinion is needed, an Abby GP can issue a referral during the consultation. See online referrals for how the process works.
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