What Causes Post Nasal Drip?

A Lot of Things, It Turns Out

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What is post-nasal drip? Not too many people ask this question, since just about everybody has had that yucky sensation of mucus running down the back of your throat, forcing you to either swallow it or cough it up. So attractive. It couldn't politely come out of your nostrils like a runny nose, right? Oh, no: This mucus goes the other way, from your nose into the back of your throat, and almost seems to dare you to do anything about it.


But that's not all.

Possible Complications of Post-Nasal Drip

You've heard the expression, "insult to injury," right? Post-nasal drip is a perfect example.

Ear Infections. Your throat and middle ear are connected by the Eustachian tube, which equalizes air pressure on either side of your eardrum. All that coughing and clearing your throat to try to get rid of the mucus can push some of it into this tube. What can happen then? You guessed it: an ear infection.

If you have ear pain (which may indicate infection) during a bout with post-nasal drip, or if your "drip" lasts longer than a couple of weeks, contact your doctor. 

Sinus Infections. This is a case of double insult to injury: Sinus infections can both cause and be caused by post-nasal drip! The "caused by" part comes in when post-nasal drip prevents your sinuses from draining properly.

Sore Throat. Post-nasal drip can be accompanied by a sore throat even if the drip isn't caused by an infection.

For more information about ear and sinus infections, read:

Everything You Need to Know About Ear Infections

What Is Sinusitis?

What Causes Post-Nasal Drip?

You may be sorry you asked. Why? Because the answer is, "Just about everything." Here you go:

  • Swallowing disorders (may result in actual post-nasal drip or just cause the sensation of having it)
  • Strep throat (post-nasal drip is an uncommon strep throat symptom, but it can occur)
  • Pregnancy and other conditions that cause fluctuation of hormone levels
  • Dehydration
  • Eating spicy foods
  • Eating too many dairy products, especially if you're not drinking enough water
  • Low humidity
  • Certain medications, including contraceptives and antihypertensives to control blood pressure
  • Foreign objects stuck in the nose
  • Overuse of pseudoephedrine nasal sprays (for more information, read: What Is Rebound Congestion?)
  • Anatomical abnormalities such as a deviated septum or enlarged turbinates
  • Acid reflux (gastrointestinal reflux disease, or GERD)
  • Weather changes

"What else should I know?"

  • Post-nasal drip is a worsening of what's actually a normal condition: You always have mucus draining down your throat, but you don't usually notice it.
  • Post-nasal drip is rarely an emergency, but get medical help if you're choking, drooling. or unable to swallow.


"Post-nasal drip." American Academy of Otolaryngology - Head and Neck Surgery (2015).  

“Nasal discharge.” U.S National Library of Medicine-MedlinePlus (2013).

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