A blocked nose can feel like a small problem until it disrupts sleep, makes food taste bland and leaves your face feeling heavy. Nasal congestion causes are varied: a short-lived viral cold is common, but allergies, irritants, medicines and sinus conditions can also play a part. The pattern of your symptoms often provides more useful clues than congestion alone.
Congestion happens when the lining of the nose becomes irritated or inflamed and the blood vessels within it swell. Extra mucus may add to the blockage, but a nose can feel blocked even when very little mucus is coming out. Understanding the likely trigger can help you choose sensible self-care and recognise when professional advice is needed.
Common nasal congestion causes
Colds and other viral infections
A cold is one of the most frequent reasons for a blocked nose. Viruses irritate the nasal lining, leading to swelling, sneezing, a runny nose and sometimes a sore throat or cough. Nasal discharge may start clear and become thicker or coloured as the cold progresses. Colour alone does not reliably show whether an infection is bacterial or whether antibiotics are needed.
Most cold symptoms begin to improve over roughly one to two weeks, although a cough or feeling of nasal stuffiness can linger. Rest, fluids and time are often the mainstays of recovery. If symptoms are getting worse rather than gradually settling, it is worth seeking advice.
Allergic rhinitis
Allergic rhinitis occurs when the immune system reacts to an allergen such as pollen, house dust mites, mould or animal dander. It often causes itching in the nose or eyes, repeated sneezing, a clear runny nose and blockage. Symptoms may appear at a predictable time of year, after being around a pet, or when cleaning a dusty room.
Unlike a cold, allergy symptoms do not usually cause fever or body aches. They can, however, affect sleep, concentration and day-to-day comfort. Reducing exposure where practical may help. A pharmacist can advise on suitable options for allergic rhinitis, taking account of your symptoms, other medicines and health conditions.
Sinus swelling after a cold
The sinuses are air-filled spaces around the nose. During a cold or allergy flare, swelling inside the nose can affect how well the sinuses ventilate and clear mucus. Some people then notice pressure or tenderness around the cheeks, eyes or forehead, reduced smell, thicker nasal mucus or post-nasal drip.
These symptoms may be part of acute rhinosinusitis, often called sinusitis. Facial pressure is not always caused by sinus problems, however. Migraine, dental problems and other conditions can produce similar discomfort. A diagnosis should not be based on a headache or blocked nose alone.
Non-allergic irritants and dry air
Tobacco smoke, vaping aerosols, strong fragrances, cleaning sprays, pollution and sudden temperature changes can irritate the nasal passages. Some people develop congestion around irritants without having an allergy. Dry indoor air may also make the nose feel uncomfortable, particularly during colder months when heating is used more often.
Avoiding a clear trigger is usually more useful than repeatedly treating the symptom. If congestion occurs mainly at work or in one particular environment, consider whether an airborne irritant, dust or mould could be contributing.
Structural or longer-term reasons
A bent nasal septum, nasal polyps and enlarged nasal tissues can contribute to ongoing blockage. These causes may be more likely when one side is persistently more blocked than the other, when symptoms have lasted for months, or when there is a reduced sense of smell that does not return after a cold.
Persistent congestion can also occur in pregnancy because hormonal changes affect the nasal lining. Some medicines may contribute too. For example, using certain medicated decongestant nasal sprays for longer than directed can lead to rebound congestion, where the nose feels increasingly blocked when the spray wears off. Do not stop or change prescribed medicines without speaking to the clinician who prescribed them.
Clues that can help narrow down the cause
Timing matters. Congestion with sneezing and itchy eyes during spring or summer may point towards pollen allergy. Congestion that begins with a sore throat, tiredness and a cough is more consistent with a viral illness. Symptoms that follow a cold and include facial pressure or altered smell may suggest sinus involvement, though they still need to be considered in context.
It is also useful to notice whether the blockage is intermittent or constant, affects one or both nostrils, and improves away from home or work. Keeping a brief record of triggers, duration and treatments tried can make a conversation with a pharmacist, doctor or qualified healthcare professional more productive.
Practical self-care for a blocked nose
For mild, short-lived congestion, start with measures that are low risk and realistic to maintain. Drink enough to stay comfortable, rest where possible and avoid smoke or known irritants. Saline nasal sprays or rinses may be considered to moisten the nasal passages and help clear secretions. Use only products as directed, and follow hygiene instructions carefully for any rinse device.
Warm drinks and a shower may feel soothing for some people. Take care to avoid very hot steam or bowls of boiling water, which can cause scalds. There is limited evidence that steam meaningfully changes the course of sinus symptoms.
Paracetamol/acetaminophen or ibuprofen may help with pain or fever for some adults, if suitable for them. Ask a pharmacist before use if you have a medical condition, take other medicines, are pregnant, or are unsure which option is appropriate.
Decongestants may provide short-term symptom relief for some people, but they are not suitable for everyone. They can interact with medicines and may be unsuitable for people with certain heart, blood pressure, thyroid, prostate or eye conditions. Medicated decongestant nasal sprays should only be used for the short period stated on the product label, package leaflet or instructions for use, because prolonged use can worsen blockage.
If allergy appears likely, a pharmacist or qualified healthcare professional can discuss approaches such as allergen avoidance and appropriate allergy medicines. It can take time for some treatments to have their full effect, so use them as directed rather than taking extra doses for quicker results.
When nasal congestion needs medical advice
Seek urgent medical help for difficulty breathing, swelling around the eyes, changes in vision, severe headache, confusion, a stiff neck, or if you feel very unwell. These symptoms are uncommon, but they need prompt assessment.
Speak to a doctor or qualified healthcare professional if congestion is severe, lasts longer than expected, repeatedly returns, or is getting worse after initially improving. Advice is also appropriate for persistent one-sided blockage, recurrent nosebleeds, a high fever, significant facial swelling, severe facial pain, dental pain, or symptoms affecting sleep and daily life.
Children, people who are pregnant, and those with long-term health conditions may need more individualised advice before using over-the-counter products. If you think a medicine is causing congestion, a pharmacist or prescriber can help review it safely.
A note on sinus-focused nasal products
Nasal products are not interchangeable. Their ingredients, intended purpose, age restrictions, directions and warnings differ. If you are considering a sinus-focused nasal spray, including Nasodren®, check that it is authorised and appropriate for your market and your circumstances. Always read and follow the product label, package leaflet or instructions for use, and seek advice from a pharmacist or qualified healthcare professional if you are uncertain.
References
NHS. Common cold; Allergic rhinitis; Sinusitis (sinus infection) patient information.
National Institute for Health and Care Excellence (NICE). Clinical Knowledge Summaries: Sinusitis (acute).
Allergic Rhinitis and its Impact on Asthma (ARIA). Allergic rhinitis guidance.
This content is for general information only and does not replace advice from a qualified healthcare professional. Always read and follow the product label, package leaflet or instructions for use. Seek medical advice if symptoms are severe, persistent, worsening, recurrent or concerning.
A blocked nose is often temporary, but it should not become something you simply put up with indefinitely. Pay attention to the pattern, give sensible self-care time to work, and ask for advice when the symptoms do not fit the usual course.