Post-Nasal Drip: Causes and How to Get Rid of It

What post-nasal drip feels like

Your nose and sinuses make about a liter of mucus a day. Normally you swallow it without noticing. Post-nasal drip becomes noticeable when mucus is increased or thicker, or when the throat is more sensitive. You may notice:

• constant need to clear your throat
• a tickle, lump or "something stuck" feeling in the throat
• cough, especially lying down or on waking
• a sore or scratchy throat in the morning
• hoarse voice
• nausea from swallowed mucus, or bad breath

Doctors call cough caused by post-nasal drip upper airway cough syndrome (UACS). It is one of the three most common causes of chronic cough, along with asthma and reflux.

Causes of post-nasal drip

Colds and viral infections

A common cold increases mucus, which thickens over a few days. Drip and cough can linger 2 to 3 weeks after other symptoms fade.

Allergies

Allergic rhinitis from pollen, dust mites, mold or pets causes clear, watery mucus, sneezing, itchy eyes and nose. It may be seasonal or year-round.

Sinusitis

Acute sinusitis causes thick, discolored drip with facial pressure and blocked nose. Chronic sinusitis (12 weeks or more) causes ongoing thick drip, congestion and reduced smell, sometimes with nasal polyps.

Non-allergic rhinitis

The nose overreacts to triggers such as temperature changes, strong smells, smoke, alcohol and spicy food. Mucus is clear and watery. Older adults often have a constantly runny nose after meals (gustatory rhinitis).

Other causes

• Pregnancy: hormones swell nasal linings.
• Medicines: some blood pressure drugs, birth control pills, and overuse of decongestant sprays (rebound congestion).
• Dry air: thickens mucus.
• Structural problems: a deviated septum or enlarged turbinates impede drainage.
• Acid reflux: GERD and laryngopharyngeal reflux irritate the throat, causing throat clearing and a feeling of mucus even without extra mucus.

Clues to the cause

How it is diagnosed

Diagnosis is usually based on symptoms and an examination of the nose and throat, which may show cobblestone bumps at the back of the throat. A doctor may try treatment first: if cough improves with nasal treatment, post-nasal drip was the likely cause. Other tests include nasal endoscopy, a CT scan of the sinuses for chronic sinusitis, allergy testing, and checks for asthma or reflux if cough persists.

How to stop post-nasal drip

Home remedies

• Saline nasal rinse or spray: flushes mucus and allergens. Use distilled, sterile or boiled-then-cooled water for rinse bottles.
• Drink plenty of fluids to keep mucus thin.
• Humidifier in dry rooms, cleaned regularly.
• Raise your head with an extra pillow to reduce night cough.
• Steam from a shower.
• Avoid triggers: smoke, strong perfumes, and alcohol if it worsens symptoms.

Over-the-counter medicines

• Steroid nasal sprays (fluticasone, budesonide, triamcinolone): best for allergic and non-allergic rhinitis. They take several days to work fully. Aim the spray toward the outer wall of the nostril.
• Antihistamines: non-drowsy types for allergies. Older sedating antihistamines dry mucus and can help cough from a cold, but cause drowsiness.
• Decongestants: short-term only. Nasal sprays for no more than 3 days. Oral decongestants are not suitable with high blood pressure, heart disease or glaucoma.
• Guaifenesin may thin mucus.

Prescription treatments

• Ipratropium nasal spray for watery drip from non-allergic rhinitis.
• Antibiotics only for bacterial sinusitis.
• Allergen immunotherapy for persistent allergies.
• Reflux treatment if reflux is part of the problem.
• Surgery for nasal polyps, a deviated septum or chronic sinusitis that does not respond.

Frequently asked questions

How do I stop post-nasal drip at night?

Raise your head with an extra pillow, use a saline rinse before bed, run a humidifier, drink fluids during the day, and use a steroid nasal spray daily if allergies or rhinitis are the cause. Avoid eating late if reflux is part of the problem.

Can post-nasal drip cause a cough that won't go away?

Yes. Post-nasal drip, called upper airway cough syndrome, is one of the most common causes of a cough lasting more than 8 weeks. Treating the nose with steroid sprays or antihistamines often settles the cough within a few weeks.

Is post-nasal drip a sign of COVID?

It can occur with COVID-19, just as with any cold-like virus. A test helps if you also have fever, sore throat, loss of smell or recent exposure. Long-lasting drip without other symptoms is more likely allergies or rhinitis.

Can acid reflux feel like post-nasal drip?

Yes. Reflux reaching the throat causes throat clearing, a lump feeling, hoarseness and cough that mimic post-nasal drip. Clues to reflux include heartburn, symptoms after meals or lying down, and a sour taste.

How long does post-nasal drip last?

After a cold, it usually clears within 1 to 3 weeks. With allergies, it lasts as long as exposure continues unless treated. Drip lasting more than 12 weeks may mean chronic sinusitis or rhinitis and should be assessed.