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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, usually. Video assessment of the cause, with a treatment plan and a prescription when it helps.
- Symptoms: a blocked or runny nose, mucus dripping down the back of the throat, constant throat clearing and a feeling of a lump in the throat.
- Causes: most often a cold, an allergy, sinusitis or irritants such as smoke; less often nasal polyps or acid reflux.
- How long: catarrh after a cold usually clears within 2 to 3 weeks; see a doctor if it lasts longer than that or keeps coming back.
- Emergency: catarrh is not dangerous, but call 112 for swelling around an eye, double vision, or a severe headache with a stiff neck.
Catarrh on its own is not urgent. Do not book a video appointment if a blocked nose or sinus pain comes with swelling or redness around an eye, double or reduced vision, a severe headache, a stiff neck or confusion. These can mean an infection has spread: call 112.
Can an online doctor treat catarrh?
Yes. Catarrh is diagnosed from your symptoms and their pattern, and a doctor can assess both by video. The doctor works out the likely cause, such as a lingering cold, an allergy, sinusitis or reflux, and recommends the treatment that fits it. A blocked nose on one side only, nosebleeds or a loss of smell that persists need an examination in person.
How an online consultation helps with catarrh
- The cause behind the mucus: Catarrh is a symptom, not a disease. The doctor works out whether infection, allergy, irritation, polyps or reflux is driving it, because each is treated differently.
- Treatment that matches: Saltwater rinses, steroid nasal sprays, antihistamines and reflux treatment each help a different cause. You get the one that fits yours.
- Decongestants used safely: Decongestant sprays work quickly but cause rebound blockage if used for more than 5 to 7 days. The doctor explains how to use them, or what to use instead.
- Warning signs checked: One-sided blockage, bleeding, a lost sense of smell and facial pain that will not settle are checked, and the doctor arranges an examination when they are present.
What the doctor checks in an online catarrh consultation
The consultation follows a fixed order, and the warning signs come first. The doctor asks about:
- Warning signs: swelling around an eye, changes in vision, a severe headache, a blocked nose on one side only, nosebleeds, or blood in the mucus.
- How long and how it started: after a cold, with the seasons, all year round, or with no clear trigger.
- Allergy clues: sneezing, itchy eyes or nose, and symptoms that are worse with pollen, dust or pets.
- Sinus and reflux clues: facial pain or pressure, a reduced sense of smell, heartburn, a sour taste or a hoarse voice in the morning.
- What you have tried: saltwater rinses, decongestant sprays and for how long, antihistamines and steroid sprays.
Before the call, think about when the catarrh started and what makes it better or worse, and have any sprays or medicines you use to hand. The doctor may ask you to tilt your head back so the inside of your nose can be seen with your phone torch.
Catarrh and post-nasal drip symptoms
Catarrh is a build-up of mucus in the nose and sinuses, and of phlegm at the back of the throat. It happens when the lining of the nose and throat swells and makes extra mucus. Symptoms include:
- a constantly blocked or runny nose
- a feeling that mucus is dripping down the back of your throat (post-nasal drip)
- a frequent need to swallow or clear your throat
- a feeling of a lump or something stuck in your throat
- a persistent cough, often worse at night or when lying down
- a crackling feeling in the ears, or slightly muffled hearing
- a reduced sense of smell and taste, and sometimes a headache or facial pain
Catarrh is uncomfortable and frustrating, but it is not dangerous. The mucus can be clear, white, yellow or green, and the colour alone does not mean you need antibiotics.
What is post-nasal drip?
Glands in the nose and throat make about 1 to 2 litres of mucus a day. It keeps the lining moist, traps dust and germs and helps fight infection, and you normally swallow it without noticing. Post-nasal drip is when you do notice it: extra or thicker mucus collects in the throat or drips from the back of the nose, causing a tickle, frequent swallowing, throat clearing, a gurgling voice and often a cough at night. The drip itself is not contagious, though a cold behind it can be.
What causes catarrh?
Catarrh is the body’s response to infection or irritation. The common causes are:
- Colds and other viral infections: the most common cause, settling as the cold clears.
- **Sinusitis:** with facial pain or pressure, thick mucus and a reduced sense of smell.
- Allergies: hay fever and year-round allergies to dust mites, pets or mould.
- Irritants: cigarette smoke, pollution and dry air.
- Nasal polyps: soft, painless growths inside the nose that cause blockage, post-nasal drip and a loss of smell.
- Acid reflux: stomach acid reaching the throat, causing throat clearing and a feeling of mucus.
- Other triggers: cold or changing weather, dry heated air, spicy food, pregnancy and other hormonal changes, some medicines such as the contraceptive pill and some blood pressure tablets, and a crooked septum inside the nose.
Some people have catarrh for months without any of these, which is called chronic catarrh. Its cause is not fully understood; it may come down to how mucus moves through the nose, or to extra sensitivity at the back of the nose and throat.
Is it a cold, an allergy, sinusitis or reflux?
The pattern of your symptoms points to the cause, and the cause decides the treatment.
Swipe sideways to compare →
| Clue | Likely cause | What usually helps |
|---|---|---|
| Started with a cold, improving within 1 to 2 weeks | A lingering cold | Fluids, saltwater rinses and time |
| Sneezing, itchy eyes and nose, worse with pollen, dust or pets | Allergic rhinitis | Antihistamines, a steroid nasal spray, avoiding triggers |
| Facial pain or pressure, thick mucus, reduced smell, for more than 10 days | Sinusitis | Saltwater rinses, painkillers, sometimes a steroid nasal spray |
| Constant blockage on both sides and a loss of smell, for months | Nasal polyps | Steroid nose drops or spray; specialist review |
| Throat clearing, a sour taste, worse after meals or lying down | Acid reflux | Reflux treatment and changes to eating |
| Blocked on one side only, with bleeding or blood in the mucus | Needs an examination | Ear, nose and throat referral |
What can be mistaken for post-nasal drip?
Some problems feel like mucus in the throat without any extra mucus. Acid reflux irritates the throat and makes you clear it, and a swallowing problem, where food or drink backs up in the throat, can feel the same. Food that sticks, pain on swallowing or weight loss need a doctor’s review.
How long does catarrh last?
Catarrh after a cold usually clears within a few days to a few weeks, as the infection settles. Sinusitis usually takes 2 to 3 weeks. Catarrh caused by an allergy lasts as long as you are exposed to the trigger, and chronic catarrh can go on for months.
See a doctor if catarrh lasts more than a few weeks, or you develop new symptoms such as a sore throat, difficulty swallowing or a loss of smell. A blocked nose on one side that does not go away, nosebleeds or blood in the mucus need an examination in person, because rarely they are caused by a growth in the nose.
Which catarrh treatment might the doctor recommend?
Treatment follows the cause. This is the decision framework the doctors use, aligned with NHS guidance and the NICE guideline on acute sinusitis (NG79).
Swipe sideways to compare →
| What you have | Likely first step | Suitable for online care? | When in-person care is needed |
|---|---|---|---|
| Catarrh after a cold, for less than 3 weeks | Saltwater rinses, fluids and steam from a shower | Usually yes | If you develop swelling around an eye or changes in vision |
| Catarrh with allergy symptoms | An antihistamine and a steroid nasal spray | Usually yes | If symptoms persist despite treatment |
| Sinus symptoms for more than 10 days without improving | A high-dose steroid nasal spray; sometimes a back-up antibiotic | Usually yes | If you are very unwell or get eye or head symptoms |
| Catarrh with heartburn or a sour taste | Treatment for reflux | Usually yes | If food sticks or you lose weight |
| Constant blockage and a loss of smell for months | A steroid nasal spray or drops, and referral if needed | Assessment and referral | For an examination of the nose |
| Swelling around an eye, vision changes or a severe headache | Emergency care | No | Call 112 now |
Catarrh that will not clear? A doctor can tell you what is likely to be causing it.
See available times →Treatment options for catarrh
What you can do yourself
- Rinse your nose with salt water up to 3 times a day, using a pharmacy kit or a homemade solution made with boiled water that has cooled. Make a fresh solution each day.
- Drink plenty of water, and sip ice-cold water instead of clearing your throat or coughing.
- Breathe in the steam from a hot shower, or use a humidifier, and avoid warm, dry air.
- Avoid triggers such as cigarette smoke and, if you have an allergy, pollen, dust or pets.
- Use decongestant sprays for no more than 5 to 7 days, because longer use makes the blockage worse.
Mucus in the throat at night
The cough and throat clearing are often worse at night. These steps help, depending on the cause:
- Rinse your nose with salt water before bed, and keep the bedroom air from getting too dry, for example with a humidifier.
- If pollen or dust is the trigger, shower before bed after time outdoors, and use covers on pillows and the mattress against dust mites.
- If reflux is behind it, raise the head of the bed by 15 to 20 cm, and do not eat or drink for 3 hours before going to bed.
Prescription treatment
A prescription is never issued without a consultation. Depending on the cause, the doctor may prescribe a steroid nasal spray, which works over days to weeks rather than straight away, an antihistamine, or a medicine that reduces stomach acid. An antibiotic is considered only for sinusitis that has lasted more than 10 days without improving. If the doctor prescribes, use the prescription at a pharmacy near you.
What does not help
Antibiotics do not help catarrh from a cold or an allergy, and green mucus alone is not a reason to take them. Cough mixtures and mucus-thinning medicines have little evidence of benefit, and there is little evidence that herbal remedies help.
Special situations
Catarrh in pregnancy
A blocked nose is common in pregnancy, because hormones make the lining of the nose swell. Saltwater rinses are safe; ask the doctor before using decongestants or other medicines.
Catarrh and asthma
Catarrh from an allergy or sinusitis can make asthma harder to control, and treating the nose often helps the chest too. Mention your asthma and inhalers to the doctor. Read more about asthma.
Catarrh while travelling
Dry cabin air and air conditioning thicken mucus. Drink water regularly and carry a saltwater spray. If your ears feel blocked when flying, swallow or yawn as the plane descends.
Children
Mobi Doctor consultations are for adults aged 18 and over. A child who is unwell needs a paediatrician or a local doctor in person, and emergency signs in a child mean 112.
When catarrh is treated online, and when you need in-person care
Treated online: catarrh after a cold, post-nasal drip, allergic rhinitis, sinusitis without warning signs, throat symptoms from reflux, and advice on rinses and sprays.
In-person care: a blocked nose on one side with bleeding, a lasting loss of smell, suspected nasal polyps that need examining, swelling around an eye or changes in vision, and catarrh that persists despite treatment.
When to get in-person care
Call 112 or go to an emergency department now for:
- swelling or redness around an eye, or a bulging, painful eye
- double vision or reduced vision
- a severe headache with a stiff neck, confusion or sensitivity to light
- swelling over the forehead
Get medical advice the same day for:
- severe facial pain with a high temperature
- symptoms that improved and then got much worse
- difficulty swallowing
How Mobi Doctor works
- Book a time that suits you: daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, and the exact price is shown before you pay.
- Speak to a licensed doctor about your catarrh: say how long it has lasted and what makes it worse, and have any sprays or medicines you use to hand.
- Leave with a plan: what to do, what to take and for how long, and which signs mean you should be seen in person. If the doctor prescribes, use the prescription at a pharmacy near you.
No sign-up needed
Catarrh can have more than one cause. Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Sinusitis can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about catarrh
What is catarrh?
Catarrh is a build-up of mucus in the nose and sinuses and of phlegm at the back of the throat. It happens when the lining of the nose and throat swells in response to an infection, an allergy or an irritant. It is uncomfortable but not dangerous.
What is post-nasal drip?
Post-nasal drip, the throat side of catarrh, is the feeling of mucus collecting in the throat or dripping from the back of the nose. The nose and throat make about 1 to 2 litres of mucus a day, which you normally swallow without noticing; with a cold, an allergy or sinusitis there is more of it, or it is thicker, so you feel it and keep clearing your throat.
What causes post-nasal drip?
Post-nasal drip, the catarrh you feel running down the back of the throat, is most often caused by a cold, an allergy such as hay fever, or sinusitis. Nasal polyps, irritants such as smoke, acid reflux, cold or dry air, spicy food, pregnancy and some medicines can also set it off.
How do I get rid of catarrh or phlegm in my throat at home?
For catarrh, rinse your nose with salt water up to 3 times a day, drink plenty of water, breathe in steam from a hot shower and avoid smoke and other triggers. If an allergy, sinusitis or reflux is behind it, treating that cause, for example with a steroid nasal spray, usually helps.
How long does catarrh last?
Catarrh after a cold usually clears within a few days to a few weeks. Sinusitis usually takes 2 to 3 weeks, and catarrh caused by an allergy lasts as long as the trigger is around. See a doctor if it lasts more than a few weeks.
Can catarrh be prevented?
Not the catarrh of a cold, but catarrh that keeps returning can be: treat hay fever and dust-mite allergy with a daily antihistamine or steroid nasal spray through the season, rinse the nose with salt water when you have a cold, keep indoor air humid in winter and free of smoke, drink enough water so mucus stays thin, manage acid reflux with smaller evening meals, and have nasal polyps or chronic sinusitis assessed rather than living with them.
Why do I feel like I have mucus stuck in my throat all the time?
Constant mucus in the throat is usually post-nasal drip from an allergy, sinusitis or a lingering cold, or irritation from acid reflux or smoking. Some people have chronic catarrh with no clear cause. Sipping ice-cold water instead of clearing your throat helps, and a doctor can work out which cause applies.
How can I reduce phlegm in my throat at night?
For night-time catarrh, rinse your nose with salt water before bed, keep the bedroom air from getting too dry, and avoid allergy triggers in the bedroom. If reflux is the cause, raise the head of the bed and do not eat or drink for 3 hours before going to bed.
What could be mistaken for post-nasal drip?
Acid reflux and swallowing problems can feel like catarrh in the throat without any extra mucus. Food that sticks, pain on swallowing or weight loss need a doctor’s review rather than more nasal sprays.
Does green mucus mean I need antibiotics?
No. Mucus often turns yellow or green during a cold or other viral infection. Colour alone does not mean a bacterial infection, and antibiotics do not help catarrh from a cold or an allergy.
Can an online doctor treat catarrh?
Yes. A doctor can assess catarrh by video, work out the likely cause and recommend or prescribe treatment such as a steroid nasal spray or an antihistamine. You can use the prescription at a pharmacy near you. One-sided blockage with bleeding needs an examination in person.
When should I see a doctor about catarrh?
See a doctor if catarrh lasts more than a few weeks, keeps coming back, or comes with a loss of smell, a sore throat or difficulty swallowing. A blocked nose on one side with nosebleeds needs an examination. Call 112 for swelling around an eye or vision changes.
- Catarrh, NHS, National Health Service (UK), reviewed 16 June 2026.
- Catarrh, HSE, Health Service Executive (Ireland), reviewed 30 August 2026.
- Sinusitis (acute): antimicrobial prescribing (NG79), NICE, National Institute for Health and Care Excellence, 2017.
- Allergic rhinitis, NHS, National Health Service (UK), 2026.
- Nasal polyps, NHS, National Health Service (UK), reviewed 29 June 2023.
- Symptoms of nasal and sinus cancer, NHS, National Health Service (UK), 2025.
- Post-nasal drip, ENT Health, American Academy of Otolaryngology–Head and Neck Surgery, reviewed August 2018.
- Postnasal drip, Cleveland Clinic, reviewed 26 May 2022.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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