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, and cilia.
- Increased thin clear secretions
- Vasomotor rhinitis
- Increased thick secretions
- Decreased secretions
- 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 mucous which 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 by increasing irritation.
- Growths or swellings in the food passages
- 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 contributes to the reflux.
- May slow or prevent the passage of liquids and/or solids.
Before treatment is started, a diagnosis must be made, This requires a detailed ear, nose, and throat exam and possible laboratory, endoscopic, and x-ray studies.
- Bacterial infection
- Structural abnormalities
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 falls, 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 in stances 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 nonprescription 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 helpful.
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 throat symptoms.
Acknowledgement is made to the American Rhinologic Society for contribution to this leaflet. Rhinology encompasses the diagnosis and surgical and non-surgical management of disorders of the nose, sinuses, and upper airway.
©1993. American Academy of Otolaryngology-Head and Neck Surgery, Inc. This leaflet is published as a public service. The material may be freely used so long as attribution is given to the American Academy of Otolaryngology-Head and Neck Surgery, Inc., Alexandria, VA.