Cough, Chronic


What should I know about chronic cough?

What is a cough? Well, the medical world describes a cough as an explosive expiration that provides a protective mechanism for clearing the tracheobronchial tree of secretions and foreign material. (1) Did you know that a cough is one of the most common symptoms for which patients seek medical help? Reasons include discomfort from the cough itself, interference with normal lifestyle, and fear of the connection with cough to some underlying illness.

Coughing may be initiated either voluntarily or as a reflex. Cough receptors are located in the pharynx, stomach, external auditory canal, diaphragm, nose, and the large airways of the tracheobronchial tree. These receptors react to a stimulus and then initiate the cough reflex. (2) Coughs can be brought on by inhaling things that irritate the airways such as smoke, dust, or fumes; or by breathing in such things as contents of the stomach, upper airway secretions, or foreign bodies. When the irritations are due to upper airway secretions, as is seen in postnasal drip, or gastric contents, as in gastroesophageal reflux disease (GERD), the actual cause may go unrecognized and the cough may be persistent. Prolonged exposure to irritants often causes airway inflammation, which itself can trigger cough, and make the airway more sensitive to other irritants.

Any disorder that causes inflammation, irritation, constriction, or compression of airways can lead to coughing. Airway inflammation commonly results from bacterial or viral infection. In viral bronchitis, airway inflammation sometimes persists long after the acute symptoms are gone, thereby producing a prolonged cough lasting for several weeks. The duration of a cough is a vital clue to its cause. The most common causes of chronic cough are postnasal drip, bronchial asthma, GERD, chronic bronchitis, and bronchiectasis. (3)

The smoking of cigarettes, pipes, and cigars irritates the airways and reduces the efficiency of the ciliated cells that move particle-laden mucus upwards and outwards causing a characteristic hacking "smoker’s cough." There are many other factors that would be associated with coughing and your healthcare professional is the best person to help you determine the cause. Some of the more serious causes include congestive heart failure, and lung diseases.

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

Chronic cough is not considered a disease, but rather is a symptom of some other condition or illness. It becomes important to ask questions about what circumstances surround the cough to help understand its cause.
Some of these questions include;

  1. Does the chronic cough occur with other symptoms of a respiratory infection?
  2. Is there wheezing?
  3. Does it occur during only one season of the year?
  4. Is there also runny nose and constant throat clearing?
  5. Is there a feeling of heartburn or burning sensation in the throat?
  6. Is there also a fever and a need to cough up mucus?
  7. Is there sputum? What is the sputum like? (thick or thin, color)
  8. Is there exposure to cigarette smoke or other pollutants?
  9. Do you take ACE inhibitors?
  10. Do you have HIV?

Chronic cough is generally a symptom of some other health condition. Consult a healthcare professional about the presence of a persistent cough.

    Treatment Options


    Before you can treat a cough, you have to know what the cause of the cough is. Different coughs require different therapies. Your healthcare professional may recommend a treatment that is specific to your particular cough which could range from bronchodilators to simply removing the offending agent, such as cigarette smoking.

    Sometimes a cough is providing a very useful function and if you are not bothered by it, your practitioner may suggest leaving it alone so that it can do its job. If the cough is not productive and needs to be suppressed, an antitussive agent may be prescribed. Two examples of antitussive drugs would be dextromethorphan and codeine. These drugs work on the cough center in the brain and extend the time between coughing episodes.

    A cough that produces large quantities of sputum should not be suppressed, since retention of secretions in the tracheobronchial tree may lead to severe infection. The use of expectorants such as guaifenesin may help in loosening and thinning bronchial secretions to make coughs more productive.

    Nutritional Suplementation

    Vitamin C

    In some cases, a cough can be caused by allergies or an upper respiratory infection. These coughs may be of varying duration. (4) It is now known that ascorbic acid exerts an antihistaminic effect by directly metabolizing histamine. (5) , (6) Therefore, if the inflammatory condition associated with an allergy or upper respiratory infection is causing a cough, vitamin C might be therapeutically useful.

    Omega-3 Fatty Acids

    If a chronic cough is related to an inflammatory condition, initiating therapy with omega-3 fatty acids might be helpful. The omega-3 fatty acids are known to promote the synthesis of the PGE3 prostaglandins, which have anti-inflammatory activity. (7)


    Quercetin is an agent with known antioxidant and anti-inflammatory properties. (8) Thus, there a possibility that quercetin could provide some benefit in individuals who are plagued with a chronic cough. Rather than being used as a primary therapeutic agent, quercetin could be used for adjunctive support.

    Herbal Suplementation

    English Ivy

    As a medicinal agent, ivy leaf traditionally has been used in the symptomatic relief of acute and chronic respiratory inflammation, as an anthelmintic and as an agent to reduce fever and cause diaphoresis. (9) There has not been a considerable amount of research on the clinical uses of ivy, yet traditional healers and European pharmacists readily profess the therapeutic value of this plant.

    There have been several studies that have reported favorable clinical results in the use of a proprietary dried ivy leaf extract in the management of upper respiratory problems. One such report was a randomized, double-blind crossover study involving 25 school-age children aged 10-15 years with chronic obstructive pulmonary disease (COPD). (10)

    Another double-blind, randomized, controlled study consisting of 99 individuals with chronic bronchitis, compared a proprietary dried ivy leaf extract with the pharmaceutical ambroxol, a synthetic mucolytic. (11) Ivy leaf extract reported to be equivalent to that of the synthetic chemical in relieving chronic bronchitis. Another multi-center study reported that a proprietary syrup of ivy extract was effective in the management of recurrent obstructive respiratory disease in children aged 6 to 15 years, with a daily dosage of 6 teaspoonfuls. (12) Coughing, expectoration, and pulmonary function improved significantly during the study.


    Oregano has been used as a cooking spice and also as a medicinal agent for centuries. Oregano volatile oil has been used traditionally for respiratory disorders such as coughs, bronchial catarrh, and as an expectorant; also for dyspepsia, rheumatoid arthritis, and urinary tract disorders. (13) Oregano oil is now used as an antifungal and antibacterial agent in various conditions. (14) The active constituents in oregano, thymol and carvacrol, have reported antibacterial properties, aiding in decreasing cough and respiratory distress. (15)


    Bromelain is a general name for a family of sulfhydryl proteolytic enzymes obtained from Ananas comosus, the pineapple plant. It is usually classified as either fruit bromelain or stem bromelain depending on its source, with all commercially available bromelain being derived from the stem. The German Commission E approves the use of bromelain in surgical swelling, particularly of the nasal sinuses. (16) Bromelain is used clinically in conditions such as upper respiratory congestion, soft tissue inflammation and arthritis, dyspepsia, and dysmenorrhea.

    Mucolytic: A decrease in the volume and purulence of sputum was reported with the use of bromelain in a clinical study of 124 patients hospitalized with chronic bronchitis, pneumonia, bronchopneumonia, bronchiectasis, or pulmonary abscesses. (17)


    1. Weinberger SE, Braunwald E. Cough and Hemoptysis. In: Fauci As, Braunwald E, Isselbacher KJ, et al, eds. Harrison’s Principles of internal Medicine, 14th ed. New York: McGraw-hill; 1998:194-196.
    2. Zervanos NJ, Shute KM. Acute, disruptive cough. Postgrad Med. 1994;95:153.
    3. Irwin RS, Curley FJ, French CL. Chronic cough. Am Rev Respir Dis. 1990;141:640.
    4. Bucca C, et al. Effect of ascorbic acid on increased bronchial responsiveness during upper airway infection. Respiration. 1989;55(4):214-9.
    5. Johnston CS. The antihistamine action of ascorbic acid. Subcell Biochem. 1996;25:189-213.
    6. Johnston CS, et al. Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. J Am Coll Nutr. Apr1992;11(2):172-6.
    7. Heller A, Koch T. Immunonutrition with omega-3-fatty acids. Are new anti-inflammatory strategies in sight? Zentralbl Chir. 2000;125(2):123-36.
    8. Ramero J, et al. Pharmacologic modulation of acute ocular inflammation with quercetin. Ophthalmic Res. 1989;21(2):112-7.
    9. Blumenthal M, ed. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medical Communications; 2000.
    10. Gulyas A, Repges R, Dethlefesen U. Systematic Therapy of Chronic Obstructive Respiratory Disease in Children. Atemwegs und Lungenkrankheiten. 1997;23:291-294.
    11. Meyer-Wegener J, Liebscher K, Hettich M, Kastner HG. Ivy versus Ambroxol in Chronic Bronchitis. Zeitchrift fun Allgemeinmedizin. 1993;69:61-66.
    12. Lassig W, Generlich H, Heydolph F, Paditz E. Efficacy and Tolerance of Ivy-Containing Cough Medications. TW Pediatric. 1996;489.
    13. Leung, et al. Encylopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics. New York: Wiley Interscience Publication; 1996:398-400.
    14. View Abstract: Dorman HJ, et al. Antimicrobial agents from plants: antibacterial activity of plant volatile oils. J Appl Microbiol. Feb2000;88(2):308-16.
    15. View Abstract: Didry N, et al. Antibacterial activity of thymol, carvacrol and cinnamaldehyde alone or in combination. Pharmazie. Apr1993;48(4):301-4.
    16. Blumenthal M, et al, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications; 2000:33-35.
    17. View Abstract: Schafer A, Adelman B. Plasmin inhibition of platelet function and of arachidonic acid metabolism. J Clin Invest. 1985;75:456-461.