Post-Nasal Drip - Causes, Symptoms & Treatments

Upper Airway Cough Syndrome

Woman with a cough.
Woman with a cough. Ariel Skelley / Getty Images

 If you've ever had a particularly nasty bit of phlegm in the back of your throat, you've experienced post-nasal drip, also known as upper airway cough syndrome (UACS) & postnasal drip syndrome (PNDS).

What is Post Nasal Drip?

Think of it like a runny nose in the back of your throat. The nose and throat normally house mucous. Mucous traps bacteria and keeps unwanted debris out, serving an important function in immunity.

Excess mucous is swallowed unconsciously most of the time, but when conditions such as a cold or flu arise, the ability to move mucous can change and cause a build up mucous or excessively thin or thick secretions. Here are some conditions that can affect post-nasal drip:

  • infections such as the common cold, flu or other viruses
  • allergies
  • temperature of the environment
  • pregnancy
  • eating spicy foods
  • meducation side effects including birth control and high blood pressure medications
  • structural abnormalities in the nasal passageways or sinuses (ie. nasal polyps, deviated septum)
  • dry air
  • dehydration
  • eating a lot of dairy products
  • exercise

Symptoms of Post-Nasal Drip

Symptoms of post-nasal drip are often non-specific to the reason for your post-nasal drip. Some people may be very bothered by post-nasal drip while others might seem unaffected. Symptoms may include:

  • difficulty swallowing
  • having to swallow more frequently
  • feeling like there's a lump in your throat
  • persistent coughing
  • a constant need to clear your throat
  • hoarseness
  • sore throat or itchiness in your throat
  • stomachache

Diagnosing Post Nasal Drip

Post nasal drip is actually a symptom of an underlying problem so your doctor's focus should be on finding the root cause of your post-nasal drip.

If an acute infection can be ruled out then you may need allergy testing or you may need to see an ear, nose, throat doctor to be checked for sinus abnormalities such as deviated septum or nasal polyps. You may also wish to talk to your physician about any medications you are taking in case your post-nasal drip is a side effect.

Treatment of Post-Nasal Drip

Finding the cause of your post-nasal drip and treating the underlying issue is ideal. For example if you have a sinus infection you may need antibiotics. If you are suffering from allergies you may benefit from the use of an antihistamine.

For non-infectious or other disease-related causes, treatment of post-nasal drip focuses on correcting the consistency of your nasal secretion. If your secretions are too thick you can:

However, if your secretions are too thin you can try to:

If your post-nasal drip is caused by a bacterial infection, then antibiotics are necessary to not only treat your post-nasal drip, but to also prevent any further complications from an untreated illness.

If one of your main symptoms is a cough, your doctor will likely prescribe you a decongestant and an antihistamine. If after 2-weeks you still do not resolution of your cough, then your doctor may try a nasal steroid.

When to Call Your Doctor

Call your doctor if post-nasal drip is accompanied by severe symptoms such as a fever or difficulty breathing, or if your symptoms have lasted longer than a few weeks. Also see your doctor if you notice a thick, foul-smelling discharge.

It may eventually be necessary to see a specialist to identify and treat the cause. Some people believe that if the color of mucous is green or yellow, it indicates a viral infection.

This is not always true. Most colds are caused by viruses, so don't expect to be given an antibiotic.

Post-nasal drip is very common and rarely serious, though it can be caused by some conditions that require medical intervention. If you are unsure or your symptoms are not manageable, it's best to call your doctor.


American Academy of Otolaryngology - Head and Neck Surgery. Post-Nasal Drip.

Coughlin, L. (2007). Cough: Diagnosis and Management. Am Fam Physician. 75(4):567-575.

Medline Plus Medical Encyclopedia. Nasal Discharge. Updated December 2017.