Quick answer. A blocked nose is most often caused by a common cold or allergic rhinitis, with chronic sinusitis, nasal polyps and a deviated septum as longer-lasting causes; persistent one-sided blockage with bloody discharge in an adult should be checked by an ENT specialist to exclude a tumour.
A blocked nose and nasal congestion are among the most familiar symptoms there are – the feeling of being stuffed up, struggling to breathe through the nose, often with a runny nose or reduced sense of smell. In Singapore, where house dust mites and periods of haze are common triggers, congestion is an everyday complaint for many people, both young and old.
Most of the time a blocked nose is due to a cold or an allergy and clears up by itself or with simple treatment. The aim of this guide is to help you understand the common causes, recognise the less common features that deserve a closer look, and know when it is worth seeing a GP or an ENT specialist.
At a glance
| Likely cause | Typical clues | What to do |
|---|---|---|
| Common cold | Short-lived, with sore throat or cough; both sides | Self-care; usually clears in a week or so |
| Allergic rhinitis | Sneezing, itch, clear runny nose; dust or haze triggers | Avoid triggers; antihistamines or nasal sprays |
| Chronic sinusitis | Lasts weeks; facial pressure, thick discharge | See a GP or ENT specialist |
| Nasal polyps or deviated septum | Persistent blockage, often worse on one side | ENT assessment |
| One-sided with bleeding (check) | Persistent one-sided block with bloody discharge in adults | See an ENT specialist to exclude a tumour |
Red flags: when a blocked nose needs prompt attention
A blocked nose is rarely an emergency, but some features mean you should be assessed rather than left to self-treat. See an ENT specialist promptly if you have:
- A persistent blockage on one side of the nose, especially with blood-stained discharge or nosebleeds, in an adult – this should be checked to exclude a growth or tumour.
- Congestion with swelling around the eye, a bulging or displaced eye, double vision, severe headache or a high fever – this can mean a sinus infection spreading, and needs urgent medical care; go to A&E if you are unwell.
- A clear, watery discharge from one nostril after a head injury – this needs prompt medical assessment.
For ordinary congestion with none of these features, there is usually no cause for alarm.
Common cold and viral infections
The most frequent cause of a blocked nose is a common cold or other viral infection. The lining of the nose swells and produces mucus, blocking airflow, usually on both sides, and often alongside a sore throat, cough or mild fever. It typically clears within a week or so. Treatment is about comfort – rest, fluids, steam inhalation and saline rinses, with short-term use of decongestants if needed. Antibiotics do not help a viral cold. See a GP if symptoms drag on beyond about ten days, worsen after starting to improve, or come with a high fever.
Allergic rhinitis – a major cause in Singapore
Allergic rhinitis is an extremely common cause of nasal congestion in Singapore, where the warm, humid climate favours house dust mites – one of the leading triggers – and periods of haze can worsen symptoms. It causes a blocked or runny nose, sneezing, an itchy nose and eyes, and often a reduced sense of smell. Unlike a cold, it tends to persist or recur and is not accompanied by fever.
Management focuses on reducing exposure to triggers (regular washing of bedding, reducing dust, staying indoors with air filtration during haze) along with antihistamines and steroid nasal sprays. If symptoms are persistent or hard to control, a GP or ENT specialist can guide longer-term treatment.
Chronic sinusitis
Chronic sinusitis is inflammation of the sinuses lasting many weeks. It causes a persistent blocked nose, facial pain or pressure (around the cheeks, eyes or forehead), thick nasal discharge and a reduced sense of smell. It can follow repeated infections or be linked to allergy or nasal polyps. Treatment may include steroid nasal sprays, saline rinses and, where appropriate, other medications; some people benefit from ENT assessment and, occasionally, surgery. Persistent facial pain and congestion that is not settling is a good reason to be reviewed.
Nasal polyps, deviated septum and decongestant overuse
Several structural and medication-related causes can keep the nose blocked:
- Nasal polyps – soft, non-cancerous swellings of the nasal lining that can block airflow and reduce smell, often linked to long-standing inflammation.
- Deviated septum – when the wall between the nostrils is off-centre, causing a blockage that is often worse on one side and tends to be lifelong.
- Overuse of decongestant nasal sprays – using these for more than a few days can lead to rebound congestion, where the nose becomes more blocked once the spray wears off, creating a cycle of overuse. Stopping the spray, with a doctor’s guidance, breaks the cycle.
These causes are best assessed by an ENT specialist, who can examine the inside of the nose directly.
Which specialist should you see?
For most blocked noses – colds and straightforward allergic rhinitis – your GP is the right first stop. A GP can confirm the likely cause, advise on trigger avoidance, prescribe antihistamines or steroid nasal sprays, treat infections, and refer you on if the problem is persistent or unusual.
An ENT (ear, nose and throat) specialist is the key specialist when congestion is long-lasting or not responding to treatment, when chronic sinusitis or nasal polyps are suspected, when a deviated septum may need correction, or when an examination inside the nose is needed. The most important reason to see an ENT specialist directly is a persistent one-sided blocked nose with blood-stained discharge in an adult – this should be checked to exclude a tumour. And if congestion comes with eye swelling, vision changes, severe headache or a high fever, seek urgent medical care, going to A&E or calling 995 if you are seriously unwell.
Related guides
- Best ENT Clinics in Singapore — our editorial shortlist
- ENT clinics directory
- Stiff neck
- Lower back pain
- Burning feet
- Difficulty walking
Sources
- HealthHub Singapore – Allergic Rhinitis and Nasal Care
- NHS – Blocked or runny nose
- NHS – Sinusitis
- Mayo Clinic – Nasal polyps
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