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Postnasal drip

What is postnasal drip?

When excess mucus – whether it's a watery or sticky discharge – drips from the back of the nose into the upper part of the throat known as the nasopharynx, it is referred to as postnasal drip. It is often associated with catarrh, which refers to an excessive mucus build-up most often in the sinuses but also in the throat, ears, or chest.

Mucus is produced by glands located in the nose, throat and airways as well as in the digestive tract. Normally it is an immune system response to help protect the body by moistening these areas to trap and destroy foreign invaders, including viruses and bacteria. In fact, the mucus from the nose mixes with saliva and usually drips down the back of your throat throughout the day without you noticing it. However, when there is too much mucus produced in the nose or it becomes too thick, it has two options - to run from the front of your nose (a runny nose) or down the back of the throat (a postnasal drip).

What can cause a postnasal drip?

There are a number of reasons that the glands in the nose may produce excess mucus such as:

  • Colds and flu
  • Sinus infections or sinusitis - an inflammation of the sinus
  • Allergies such as a reaction to pollen, animals and dust mites
  • An object stuck in the nose - usually in a child
  • Pregnancy
  • Medications - such as blood pressure medicines and contraceptive pills
  • A deviated septum (a problem with the wall between the two nostrils), nasal polyp (a fleshy swelling inside the nose), or other physical problem within the nose
  • Cold temperatures, excess dryness or change in weather patterns
  • Spicy foods and other food triggers
  • Fumes produced by cleaning products, perfumes, smoke and other chemicals and irritants


What are the symptoms of a postnasal drip?

People with a postnasal drip may feel a constant need to clear their throat. Mucus contains inflammatory elements so it can irritate the throat, leading to a sore throat and hoarseness, and it can trigger a cough. A long-term (chronic) cough is often associated with postnasal drip.

Postnasal drip is generally more noticeable at night, especially when lying down to sleep. It can block the Eustachian tube, which joins the throat to the middle ear, leading to a painful ear infection. If sinus passages become blocked, a postnasal drip can cause a sinus infection.

How is a postnasal drip treated?

Treatment will depend on the cause. Often a postnasal drip will clear up by itself. If a viral infection or sinusitis is involved, antihistamines and decongestants may be useful, though decongestants are only for short-term relief. These can also be useful for treating postnasal drip associated with allergies, along with nasal sprays and steroid medications.

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