How long should a cough last before I worry?

In adults, a cough lasting more than 8 weeks is considered chronic and should be assessed. However, because of tuberculosis in Singapore, a persistent cough of 3 weeks or more should already prompt a medical review, especially with fever, night sweats or weight loss.

Can acid reflux really cause a cough?

Yes. Gastro-oesophageal reflux disease is one of the three most common causes of chronic cough in non-smokers. Stomach acid can irritate the throat and airways, sometimes without obvious heartburn. Your doctor can assess and treat this.

My cough started after I began a blood pressure medication. Is that linked?

It may be. A class of blood pressure drugs called ACE inhibitors is a well-known cause of a persistent dry cough. Do not stop your medication on your own; tell your doctor, who can review whether a change is appropriate.

When should I see a respiratory specialist rather than a GP?

Start with your GP or polyclinic. A referral to a respiratory physician is appropriate if your cough lasts more than 8 weeks, you have red-flag symptoms such as coughing up blood or weight loss, or if your chest X-ray is abnormal or the cause remains unclear.

Could my chronic cough be something serious like cancer or TB?

Most chronic coughs are due to treatable conditions such as post-nasal drip, asthma or reflux. However, serious causes including tuberculosis and lung cancer are possible, especially with red-flag symptoms. This is why a persistent cough should be assessed rather than simply suppressed.

Chronic Cough in Singapore: Causes and When to See a Doctor

Written & reviewed by the BestDoctors.sg editorial team · Last updated 2 Jul 2026 · General information, not medical advice

Quick answer. A chronic cough is one that lasts more than 8 weeks in adults. In people with a normal chest X-ray who do not smoke, the three most common causes are upper airway cough syndrome (post-nasal drip), asthma including cough-variant asthma, and gastro-oesophageal reflux disease (GERD). Other causes include post-viral cough, certain blood pressure medications (ACE inhibitors), smoking and COPD, and, importantly in Singapore, tuberculosis. Red-flag symptoms such as coughing up blood, unexplained weight loss, fever or night sweats, or breathlessness need prompt assessment. A persistent cough of 3 weeks or more should prompt consideration of TB. This guide explains the common causes, warning signs, and when to see a GP or respiratory physician. It is general information, not medical advice.

Almost everyone coughs from time to time, but a cough that lingers can be worrying and disruptive. In adults, a cough lasting more than 8 weeks is considered chronic and deserves medical assessment. The good news is that most chronic coughs in non-smokers with a normal chest X-ray come down to a small number of treatable causes. This guide explains those common causes, the red-flag symptoms that need prompt attention, why a persistent cough in Singapore should also prompt thinking about tuberculosis, and when to see a GP versus a respiratory physician. It is general information only and not a substitute for advice from your own doctor.

At a glance

Cough duration and what it suggests
Type	Duration	Notes
Acute	Less than 3 weeks	Often a viral infection; usually self-limiting
Subacute	3 to 8 weeks	Frequently post-infectious; assess if persistent
Chronic	More than 8 weeks	Warrants medical assessment for an underlying cause
TB consideration	3 weeks or more	Persistent cough should prompt TB assessment in Singapore

What counts as a chronic cough?

In adults, a chronic cough is generally defined as one lasting more than 8 weeks. Shorter coughs are often classified as acute (under 3 weeks, commonly viral) or subacute (3 to 8 weeks, frequently following an infection). HealthHub advises seeing a doctor if a cough does not improve within 2 weeks of self-care, gets worse, or lasts more than 8 weeks. Importantly, because of tuberculosis, a separate and lower threshold applies in Singapore: a persistent cough of 3 weeks or more should prompt medical review and consideration of TB.

The most common causes

In adults who do not smoke and have a normal chest X-ray, three causes account for the majority of chronic coughs: upper airway cough syndrome, also called post-nasal drip, where mucus from the nose or sinuses drips down the throat; asthma, including cough-variant asthma where cough is the main symptom; and gastro-oesophageal reflux disease (GERD), where stomach acid irritates the throat and airways. A Singapore hospital case series found post-nasal drip, post-infectious cough, GERD and cough-variant asthma to be the commonest causes. Often more than one factor is involved, and treating the underlying cause usually resolves the cough.

Other causes to consider

Beyond the big three, other causes include a lingering post-viral or post-infectious cough after a cold or flu, and certain blood pressure medications, particularly ACE inhibitors, which are a well-recognised cause of dry cough. Smoking, chronic bronchitis and COPD are important causes in smokers. Less common but serious causes include bronchiectasis, lung infections including tuberculosis, and lung cancer. This is why a chronic cough, especially with any warning signs, should be assessed rather than simply suppressed. If you take a blood pressure medication and have developed a dry cough, mention this to your doctor rather than stopping it yourself.

Red-flag symptoms that need prompt assessment

Some symptoms accompanying a cough warrant prompt medical attention. According to HealthHub, see a doctor if you cough up a large amount of phlegm, or bloody or pink frothy phlegm, lose weight unexpectedly, have a fever above 38.6 degrees Celsius, experience difficulty breathing, wheezing or chest pain, or cough up thick yellow or green phlegm. Coughing up blood, fever, night sweats and unexplained weight loss are also warning signs of tuberculosis. People with a weakened immune system or with heart failure, asthma or COPD should seek review sooner. Hoarseness or a change in a long-standing cough also merits assessment.

Tuberculosis: a Singapore-specific consideration

Tuberculosis remains present in Singapore, with over a thousand new cases among residents reported in 2024. Because of this, a persistent cough of 3 weeks or more should prompt consideration of TB, particularly if accompanied by coughing up blood, fever, night sweats, loss of appetite or unexplained weight loss. MOH advises people with a prolonged cough to seek medical attention early. TB is diagnosed with a chest X-ray and further tests, and is curable with several months of combination antibiotic treatment. Early diagnosis protects both you and those around you.

When to see a doctor, and costs

Your GP or polyclinic is the right first stop for a chronic cough. The doctor will take a history, examine you and usually arrange a chest X-ray, and may add spirometry to check for asthma. You may be referred to a respiratory physician if your cough lasts more than 8 weeks, if there are red-flag symptoms, or if the X-ray is abnormal or the cause is unclear. As a guide only, a subsidised polyclinic consult for an eligible Singaporean is roughly S$15 to S$20 before tests and medication, a private GP visit is commonly around S$35 to S$60 or more, a private chest X-ray often starts from around S$49, and a private specialist consult commonly ranges from about S$180 to S$400. Public-sector fees depend on subsidy eligibility, and private fees are not fixed, so confirm current charges.

Related guides

Best Respiratory & Lung Clinics in Singapore — our editorial shortlist
Asthma care
COPD care
Sleep apnoea

Sources

Last updated 21 June 2026. Prices are typical market ranges gathered from the cited sources and vary by clinic, doctor and individual case — they are not quotes. This guide is general information, not medical advice; always consult a qualified, MOH-accredited doctor before any treatment.

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