What is post nasal drip?
The nose and sinuses make about a litre or more of mucus every day. Normally you swallow it without noticing. When mucus becomes thicker, more abundant or when throat sensation is heightened, you feel it dripping down the back of the throat. This is post nasal drip (upper airway cough syndrome). The mucus and the inflammation that causes it irritate the throat, producing soreness. See postnasal drip for a full overview.
How it feels
- A sore, scratchy or raw throat, often worse in the morning.
- A feeling of mucus at the back of the throat or a constant need to swallow or clear the throat.
- A tickle or lump in the throat. See lump in throat.
- Cough, particularly at night or when lying down. See dry cough at night.
- Hoarse voice and bad breath.
- Nasal congestion, sneezing or a runny nose.
- Nausea in the morning from swallowed mucus in some people.
- No fever, usually.
Common causes
- Allergies: hay fever, dust mites, pets. See sore throat from allergies.
- Colds and viral infections.
- Sinusitis, acute or chronic. See sinus infection symptoms.
- Non-allergic and vasomotor rhinitis. See non-allergic rhinitis.
- Deviated septum, nasal polyps or enlarged adenoids.
- Dry air or cold weather, which thickens mucus.
- Acid reflux (LPR), which increases mucus production and throat irritation.
- Pregnancy and hormonal changes.
- Medications, including some for blood pressure.
- Dehydration, smoking and spicy foods.
Home remedies
- Saline nasal rinse or spray once or twice daily; use distilled, boiled or sterile water. See neti pot sinus rinse.
- Drink plenty of water and warm fluids to thin mucus.
- Gargle with warm salt water to ease soreness.
- Raise your head at night with extra pillows.
- Use a humidifier in the bedroom, cleaned regularly.
- Steam inhalation or a hot shower to loosen mucus.
- Honey and lozenges to soothe.
- Avoid irritants: smoke, strong smells and very dry air.
- Avoid constant throat clearing, which worsens irritation; sip water or swallow instead.
- Avoid late meals, alcohol and caffeine if reflux contributes.
Medicines that help
- Intranasal steroid sprays for allergic and chronic rhinitis, used daily.
- Antihistamines (second-generation, such as cetirizine, loratadine, fexofenadine) for allergy-related drip; older sedating antihistamines dry mucus but cause drowsiness.
- Azelastine or ipratropium nasal spray for a runny nose.
- Short-term decongestants (up to 3 days for sprays) with caution; oral decongestants can raise blood pressure.
- Mucolytics or guaifenesin have limited evidence but some people find them helpful.
- Antibiotics only for confirmed bacterial sinusitis.
- Reflux medicines when reflux is the cause.
- Ask a pharmacist if you have other conditions or take regular medicines.
How a doctor finds the cause
A doctor will ask about allergies, nasal symptoms, reflux, smoking and medicines, and examine your nose, throat and ears. An ENT may look inside the nose with a small camera to check for polyps, a deviated septum or sinus drainage, and arrange allergy tests or a sinus scan if needed. Treatment is often a trial of nasal sprays and rinses for 4–6 weeks, with review.
Children and post nasal drip
Children often have post nasal drip with colds, allergies and enlarged adenoids. Typical signs are a night cough, throat clearing, snoring and mouth breathing. Saline rinses, allergy control and a paediatrician-guided spray or antihistamine help. Avoid cough and cold medicines in young children, and see a doctor for a cough lasting more than 3 weeks or with noisy breathing.
When to see a doctor
- Symptoms lasting more than 3–4 weeks despite home care.
- Thick yellow-green mucus with fever, facial pain or swelling.
- Difficulty swallowing, voice change lasting more than 3 weeks or a neck lump.
- Blood in mucus, unexplained weight loss or night sweats.
- Wheeze or breathlessness.
- Symptoms in only one nostril.
- Frequent sinus or ear infections.
Three common situations
A sore throat every morning with a blocked nose in pollen season: allergy; nasal steroid, saline and an antihistamine.
A cold followed by two weeks of throat clearing and cough: post-viral drip; saline, fluids and time.
A person with morning hoarseness, throat clearing and sour taste: consider reflux as well as drip.
Key points to remember
A sore throat from post nasal drip settles when the nose is treated: saline rinses, the right nasal spray, hydration and trigger control. Avoid throat clearing and see a doctor if symptoms last over a month or have red flags. Our ENT team can find the source of the drip.
This guide is for general information and does not replace an examination by your own doctor or ENT specialist.
Questions about post nasal drip and sore throat
These answers are general information and do not replace an examination or individual medical advice.
Can post nasal drip cause a sore throat?
Yes; mucus and inflammation irritate the back of the throat, causing soreness and cough.
How do I stop post nasal drip?
Treat the cause: saline rinses, nasal steroid or antihistamine, avoid triggers and stay hydrated.
Why is it worse at night?
Lying flat lets mucus pool at the back of the throat.
Is post nasal drip contagious?
Not by itself, but a cold or infection causing it may be.
Can reflux cause post nasal drip?
Reflux can mimic or worsen it by irritating the throat and increasing mucus.
When should I see a doctor?
If it lasts more than 3–4 weeks or comes with red-flag symptoms.
Sources
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.