Glands in your nose and throat continually produce mucus (one to two quarts a day). Mucus moistens and cleans the nasal membranes, humidifies air, traps and clears inhaled foreign matter, and fights infection. Although it is normally swallowed unconsciously, the feeling of it accumulating in the throat or dripping from the back of your nose is called post-nasal drip. This sensation can be caused by excessively thick secretions or by throat muscle and swallowing disorders.
Increased thin clear secretions can be due to colds and flu, allergies, cold temperatures, bright lights, certain foods/spices, pregnancy, and other hormonal changes. Various drugs (including birth control pills and high blood pressure medications) and structural abnormalities can also produce increased secretions. These abnormalities might include a deviated or irregular nasal septum (the cartilage and bony dividing wall that separates the two nostrils).
Swallowing problems may result in accumulation of solids or liquids in the throat that may complicate or feel like post-nasal drip. When the nerves and muscles in the mouth, throat, and food passage (esophagus) aren't interacting properly, overflow secretions can spill into the voice box (larynx) and breathing passages (trachea and bronchi), causing hoarseness, throat clearing, or coughing.
Several factors contribute to swallowing problems:
Swallowing problems may also be caused by gastroesophageal reflux disease (GERD). This is a backup of stomach contents and acid into the esophagus or throat. Heartburn, indigestion, and sore throat are common symptoms. GERD may be aggravated by lying down, especially following eating. Hiatal hernia, a pouch-like tissue mass where the esophagus meets the stomach, often contributes to the reflux.
Post-nasal drip often leads to a sore, irritated throat. Although there is usually no infection, the tonsils and other tissues in the throat may swell. This can cause discomfort or a feeling that there is a lump in the throat. Successful treatment of the post-nasal drip will usually clear up these throat symptoms.
A correct diagnosis requires a detailed ear, nose, and throat exam, and possibly laboratory, endoscopic (procedures that use a tube to look inside the body), and x-ray studies. Treatment varies according to the following causes:
General measures that allow mucus secretions to pass more easily may be recommended when it is not possible to determine the cause. Many people, especially older persons, need more fluids to thin out secretions. Drinking more water, eliminating caffeine, and avoiding diuretics (medications that increase urination) will help. Mucous-thinning agents such as guaifenesin (Humibid®, Robitussin®) may also thin secretions. Nasal irrigations may alleviate thickened secretions. These can be performed two to four times a day either with a nasal douche device or a Water Pik® with a nasal irrigation nozzle. Warm water with baking soda or salt (½ to 1 tsp. to the pint) or Alkalol®, a nonprescription irrigating solution (full strength or diluted by half warm water), may be helpful. Finally, use of simple saline (salt) nonprescription nasal sprays (e.g., Ocean®, Ayr®, or Nasal®) to moisten the nose is often very beneficial.