What is Post-Nasal Drip?
Post-nasal discharge, also called post-nasal drip (PND), describes the sensation
of mucous accumulation in the throat or a feeling that mucus is dripping downward
from the back of the nose. PND can be caused by excessive or thick secretions
or throat muscle and swallowing disorders.
Normally, the glands lining the nose and sinuses produce one to two quarts
of thin mucus a day. On the surface of this mucous membrane lining, the rhythmic
beat of invisible cilia (which look like tiny hairs under the microscope) thrust
the mucus backward. Then it is swallowed unconsciously. This mucus lubricates
and cleanses the nasal membranes, humidifies air, traps and clears inhaled
foreign matter, and fights infection. Mucus production and clearance is regulated
by a complex interaction of nerves, blood vessels, glands, muscles, hormones,
Increased thin clear secretionscan be due to colds and flu (upper respiratory
viruses), allergies, cold temperatures, bright lights, certain foods and spices,
pregnancy and hormonal changes, various drugs (including birth control pills
and especially high blood pressure medications), and structural abnormalities,
such as a deviated or irregular nasal septum. (the septum is the cartilage
and bony partition which divides the nose into its , two sides, beginning at
the nostrils and extending to the back of the nasal cavity.)
Vasomotor rhinitus describes a non-allergic "hyperirritable nose," which
may feel congested, blocked or wet.
lncreased thick secretions are frequently caused by wintertime low humidity
in homes and buildings heated without adding moisture to the air. They can
also result from sinus or nose infections and some allergies, especially to
certain foods such as dairy products. If the secretions of a common cold become
thick and green or yellow it is likely that a bacterial sinus infection is
developing. Also, particularly in children, they can signify a foreign body
in the nose (such as a bean, wadded paper, piece of toy, etc.).
Decreased secretions may be caused by any of the following:
Long-term exposure to environmental irritants (such as cigarette smoke, industrial
pollutants, and automobile fumes), which can dry and damage nasal mucous membranes.
When secretions are reduced, they are usually thicker than normal and produce
the false sensation of increased mucus.
Structural abnormalities (such as nasal septal irregularities) which alter
air currents may then dry surrounding membranes. (Thus, depending on their
type, structural problems can increase or decrease secretions.)
Age. Mucous membranes commonly shrink and dry with age, causing reduced mucus
that is thicker than normal which the elderly perceive as PND.
Other less common disorders of the tissues lining the nose and sinuses can
alter mucous production or flow.
Swallowing is a complicated process by which food and fluid go from the mouth
into the esophagus (tube connecting the throat to the stomach). It requires
coordinated nerve and muscle interaction in the mouth, throat, and esophagus.
Swallowing problems may result in accumulation of solids or liquids in the
throat, which can spill into the voice box (larynx) and breathing passages
(trachea and bronchi) causing hoarseness, throat clearing, or cough.
Several factors contribute to swallowing problems:
With age, swallowing muscles often lose strength and coordination. Thus, even
normal secretions may not pass smoothly into the stomach.
During sleep, swallowing occurs much less frequently, and secretions may accumulate.
Coughing and vigorous throat clearing are often needed when awakening.
At any age, nervous tension or stress can trigger throat muscle spasms, resulting
in a sensation of a lump in the throat. Frequent throat clearing, which usually
produces little or no mucus, can make the problem worse bi increasing irritation.
Growths or swellings in the food passages may slow or prevent the passage
of liquids and/or solids.
Swallowing dysfunction may be caused by gastroesophageal reflux, which is
a return of stomach contents and acid into the esophagus or into the throat.
Heartburn, indigestion, and sore throat are common symptoms, which may be aggravated
while lying down (especially following eating.) Hiatal hernia, a pouch-like
structure at the junction of the esophagus and stomach, often contribute to
Chronic Sore Throat
Post-nasal drip often leads to a sore, irritated throat. Usually, throat cultures
will not show strep or other infections, but the tonsils and other glandular
tissues in the throat may swell, causing discomfort or a feeling of a throat
lump. Successful treatment of the post-nasal drip will usually clear up these
Before treatment is started, a diagnosis must be made. This requires a detailed
ear, nose, and throat exam and possibly laboratory, endoscopic, and x-ray studies.
Bacterial infection is treated with antibiotics, but these drugs may provide
only temporary relief. In cases of chronic sinusitis, surgery to open the blocked
sinuses or drainage pathways may be required.
Allergy is managed by avoiding the cause where possible. Antihistamines and
decongestants, cromolyn and steroid (cortisone type) nasal sprays, various
other forms of steroids, and hyposensitization (allergy shots) may be used.
However, some antihistamines may dry and thicken secretions even more; decongestants
can aggravate high blood pressure, heart, and thyroid disease (these drugs
commonly are found in nonprescription medications for colds). Steroid sprays
generally may be used safely for years under medical supervision. Oral and
injectable steroids rarely produce serious complications in short term use.
Because significant side effects can occur, they must be monitored very carefully
if used for prolonged periods.
Gastroesophageal reflux is treated by elevating the head of the bed six to
eight inches, avoiding late evening meals and snacks and eliminating alcohol
and caffeine. Antacids (e.g. Maalox, Mylanta, Gaviscon," ) and drugs
that block stomach acid production (e.g. Zantac, Tagamet, Pepcid) may be
prescribed. A trial of treatment may be suggested before x-rays and other
diagnostic studies are performed.
Structural abnormalities may require surgical correction. A septal deviation
can prevent normal drainage from the sinuses and contribute to the development
of chronic sinusitis. A septal spur (sharp projection) can cause irritation
and abnormal secretions. A septal perforation (hole) can cause crusting.
Enlarged or deformed nasal turbinates (the structures on the side walls of
the nasal cavity which regulate and humidify airflow) and/or polyps (i.e.
outgrowths of nasal membrane resulting from infection, allergy or irritants)
may cause similar problems.
It is not always possible to determine whether an existing structural abnormality
is causing the post-nasal drip or if some other condition is to blame. If
medical treatment fails, the patient must then decide whether to undergo
surgery in an attempt to relieve the problem.
In some cases, no specific cause can be found for PND. When no correctable
disease is present, attention is usually directed to thinning secretions
so they can pass more easily. This is particularly true for the elderly,
who often have inadequate fluid intake. These patients should drink eight
glasses of water a day, eliminate caffeine, and avoid diuretics (fluid pills)
if possible. Mucous thinning agents such as guaifenesin or organic iodine
may be employed. Guaifenesin (e.g. Humibid, Robitussin ) rarely produces
significant side effects. In the rare instances when organic iodine (Organidin)
causes swelling of the saliva glands or a rash, the drug must be discontinued.
Nasal irrigations may alleviate thickened or reduced secretions. These can
be performed two to six times a day either with a nasal douche device or
a Water Pik equipped with a special nasal irrigation nozzle (purchased separately).
Warm water with baking soda or salt (1/2 tsp. to the pint) or Alkalol, a
non-prescription irrigating solution (full strength or diluted by half with
warm water), may be helpful. Finally, use of simple saline non-prescription
nasal sprays (e.g. Ocean, Ayr, Nasal,) to moisten the nose is often very
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