Post-nasal drip

Post-nasal drip describes the drainage of mucus secretions from the nose or sinuses down the back of the throat, often causing cough. When associated with cough, the more correct term for post-nasal drip is 'upper airway cough syndrome'.

Causes of post-nasal drip

Post-nasal drip is usually caused by an underlying rhinitis (inflammation of lining of the inside of your nose) or sinusitis - inflammation of the sinuses - cavities within facial bones that surround your nose but it can also occur as part of other conditions such as asthma and gastro-oesophageal reflux disease (GORD).

Post-nasal drip symptoms

Aside from a cough, other symptoms that may be associated with post-nasal drip include:

  • the need to clear the throat often;
  • a 'tickle' in the throat or sore throat;
  • excess mucus (phlegm) in the throat;
  • a blocked or runny nose; and
  • hoarseness.

Post-nasal drip can also cause bad breath (halitosis).

Often there is very little for your doctor to see on examination, so post-nasal drip is often diagnosed based on your symptoms (after other possible diagnoses have been ruled out).

Post-nasal drip treatment

Treatment of post-nasal drip largely depends on the cause.

In people with allergic rhinitis (rhinitis that's caused by an allergy, such as hay fever), post-nasal drip usually responds to treatment with antihistamine and short term decongestant medicines. A saline nasal spray can also be helpful to flush the nose of allergens or irritants and thin the mucus.

Sometimes, a nasal steroid spray will also be suggested.

Avoiding substances you are allergic to (allergens) is also worthwhile. However, if the allergen is unknown, skin prick tests to identify the particular substances to which you are allergic may be recommended.

Sometimes, if the allergen cannot readily be avoided, or if the allergy symptoms are particularly severe and persistent, immunotherapy treatment might be recommended. Immunotherapy is a series of injections of small amounts of the allergen, gradually increasing in dose over a period of months to years. The therapy is often very effective in desensitising the affected person against a particular allergen.

Antibiotics may help in treating people with sinusitis that is caused by a bacterial infection.

Another general measure that can help minimise the symptoms associated with post-nasal drip is to increase fluid intake, which will thin secretions. Similarly, substances that dehydrate the body will increase the problem — examples are alcohol, caffeine and diuretic medicines.

Last Reviewed: 1 December 2010


1. Cough (revised Oct 2009). In: eTG complete. Melbourne: Therapeutic Guidelines Limited; Nov 2011. (accessed Dec 2011).
2. Chronic cough (14 May 2011). (accessed Dec 2011).
3. Nonallergic rhinitis (7 Aug 2010). (accessed Dec 2011).
4. Hay fever (29 Apr 2010). (accessed Dec 2011).


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