Nasal congestion (blocked nose): causes, red flags and treatment

Nasal congestion rarely means the nose is full of mucus. More often the lining of the nose has swollen because of infection, allergy or irritation, narrowing the passage and making it hard to breathe through. Mucus may be thin and watery, thick and discoloured or absent altogether. Congestion can alter your voice, reduce your sense of smell and taste, cause snoring and make sleeping difficult.

The pattern of onset, duration, side and accompanying symptoms usually points to the cause. A blocked nose lasting days with a sore throat suggests a cold, a seasonal blocked nose with itchy eyes suggests hay fever, facial pressure and discoloured discharge after a cold suggests sinusitis, and a nose that stays blocked for months despite treatment raises the possibility of polyps or a structural problem.

Other causes include rhinitis not due to allergy, such as reactions to smoke, strong smells or temperature changes, and overuse of decongestant sprays that causes rebound swelling. In pregnancy, hormonal changes frequently cause a blocked nose.

For a cold the NHS suggests rest, plenty of fluids, healthy food, gargling salt water for a sore throat and breathing in steam, for example sitting in the bathroom with a hot shower running. It says not to let children breathe in steam from a bowl of hot water because of scalding, and not to smoke. A pharmacist can recommend decongestant nasal sprays, drops or tablets, which should not be used by children under 6, and the NHS cautions that nasal sprays should not be used for more than a week.

For sinusitis, the NHS suggests rest, plenty of fluids, painkillers such as paracetamol or ibuprofen, avoiding allergy triggers, not smoking and cleaning the nose with a salt water solution made by mixing 1 teaspoon of salt and 1 teaspoon of bicarbonate of soda into about 1 pint of cooled boiled water. For hay fever the NHS lists petroleum jelly around the nostrils, wraparound sunglasses, showering and changing clothes after being outside, keeping windows shut, damp dusting and avoiding cutting grass. Antihistamines and steroid nasal sprays are the pharmacist treatments it names.

A blocked nose is seldom urgent, but certain features change that.

• Ask for an urgent GP appointment or get help from NHS 111 if you have sinusitis symptoms and you are very unwell, painkillers do not help or symptoms get worse, or you have a weakened immune system, for example during chemotherapy.

• Seek urgent advice for swelling or redness around the eye, a severe headache with fever and stiff neck, double vision or confusion following a sinus infection, as infection can occasionally spread to the eye socket or brain.

• See a GP if cold symptoms do not get better after 10 days, you have a high temperature for more than 3 days, you feel short of breath or have chest pain, or you have a long-term condition or weakened immune system, as the NHS cold page advises.

• See a GP if you do not get better after 7 days of pharmacy or GP treatment for sinusitis, after 3 weeks of self-care, if you keep getting sinusitis or if a child is aged 11 or younger.

• See a GP if you suspect nasal polyps, have difficulty breathing, symptoms are getting worse or you notice changes to your sense of smell.

• A blocked nostril on one side only, particularly with bleeding, a foul discharge or facial numbness, should be examined, and the NHS says a GP may refer to ENT if symptoms occur on only 1 side of the face.

• Call 999 for severe difficulty breathing, lip or throat swelling after exposure to a known allergen.

The GP asks how long the blockage has lasted, whether it is one-sided, the type of discharge, smell loss, allergy history, asthma, smoking, spray use and any previous nasal surgery or injury. They look inside the nose to see swollen lining, polyps or a deviated septum; the NHS says a GP should be able to tell if you have nasal polyps by looking inside your nose.

Allergy testing, a scope examination of the nose by an ENT specialist or a CT scan of the sinuses are reserved for persistent, recurrent or one-sided problems. The NHS says a GP may refer you to ENT if you still have sinusitis after 3 months of treatment, keep getting it or only have symptoms on one side of the face.

If sinusitis needs treatment, the NHS says a pharmacist or GP may prescribe steroid nasal sprays or drops to reduce the swelling, which may be needed for a few months, or antihistamines if an allergy is causing symptoms. Antibiotics are rarely needed because sinusitis is usually caused by a virus rather than bacteria.

For nasal polyps, steroid nose drops or spray are usually given to shrink them, sometimes with steroid tablets, usually for up to 2 weeks. If there is no improvement after about 12 weeks, the NHS says surgery to remove polyps may be suggested; it notes that polyps commonly grow back within a few years, and a steroid spray may be continued afterwards. For chronic sinusitis, functional endoscopic sinus surgery under general anaesthetic can widen blocked sinuses. If hay fever is not controlled, the GP may refer you for immunotherapy.