What Causes Increased Mucus Production in COPD?

Causes and Treatment of Excess Sputum With COPD

what causes increased mucus prodution an how is it treated and prevented?. Istockphoto.com/Stock Photo©jackethead

Mucus (also called sputum) production is a hallmark of some types of chronic obstructive pulmonary disease (COPD). Environmental irritants and other factors can result in both the increased production of mucus by cells called goblet cells, and a decreased ability to rid the lungs of mucus.

Understanding Mucus Production

Increased mucus or sputum production, is the reaction of the lungs to a constantly recurring irritant such as cigarette smoke or air pollution.

 Mucus, or sputum, is different than saliva and is composed of dead cells and debris from the lower respiratory tract.  In this sense, mucus has a function. It traps debris and organisms such as bacteria so that they can be cleared - cough up - from the lungs.

Changes in Mucus Production

An increase in the amount of mucus produced in the lung is significant, but so also are other changes, such as differences in the color of the sputum, and its tenacity - meaning the thickness or stickiness of the mucus.

What Causes Increased Mucus?

A combination of factors is usually responsible for the development of increased mucus, and can help understand why this occurs. These include:

  • Overproduction of mucus by the goblet cells
  • Hypersecretion of mucus from the goblet cells and submucosal glands
  • Decreased ability to remove mucus either due to damage to the cilia in the airways, which are the hair-like structures that help mucus move from lower in the lungs and towards the mouth, as well as decreased ability to cough, as may occur with atrophy of muscles associated with coughing.

    Substances and Conditions Which Cause Increased Mucus

    Overproduction, hypersecretion, and decreased clearance explain the mechanisms by which sputum accumulates in the lungs, but why does this occur?  Most commonly it is environmental irritants which cause the goblet cells to produce and secrete mucus while damage to the airways and in particular the cilia leads to its continued presence in the lungs (rather than being coughed up as sputum.)  With COPD, it is usually a combination of these factors which helps, in turn, to understand how treatments can provide relief.

    Common irritants include:

    • Tobacco smoke, the leading irritant responsible for excess mucus.
    • Outdoor air pollution
    • Indoor air pollution, many think of outdoor air pollution as being a big culprit in causing these symptoms, but sometimes, and often, indoor air is worse

    What Conditions are Associated with Increased Mucus Production by the Lungs?

    Conditions in which an excess production of mucus commonly occurs include:

    • Chronic bronchitis: By definition, chronic bronchitis is associated with excess mucous production in the lungs, since the diagnosis requires you to have a cough with sputum production every day for at least 3 months.
    • Bronchiectasis: Bronchiectasis is a disease in which recurrent infections lead to a widening of the airways.  Bronchiectasis often produces thick, foul smelling sputum.
    • Pulmonary edema: With pulmonary edema, sputum is often "frothy" appearing, and may have a pink color due the presence of blood.

    Treatments and Coping with Increased Sputum Production

    Just as there are several mechanisms that often work together to result in increased mucus production, a combination of different approach usually works best when coping with the symptoms.

    Avoiding Respiratory Irritants

    Certainly avoiding smoking and secondhand smoke is an important first step in decreasing the lung irritants which causes increased mucus.  Avoiding time outside when pollution levels are high can also be helpful.  As noted above, indoor air can be as important, if not more, than outdoor air.  Check out these Steps to Better Indoor Air Quality.

    Did you know that there is a fun and even aesthetically pleasing way to improve your indoor air?  Check out these houseplants which have been found - based on research performed by NASA - to improve indoor air.

    You may also want to check into the pros and cons of air purification systems that can be used in your home.

    Airway Clearance Techniques

    Airway clearance techniques are often used to relieve the symptoms of excess mucus and can include:

    • Controlled coughing - Controlled coughing is the most effective airway clearance technique.
    • Postural drainage - Postural drainage is a technique which used gravity to help hasten mucus clearance from the lungs.
    • Chest physiotherapy - Chest physiotherapy or chest percussion appears to be safe for people with bronchiectasis and may provide some relief.
    • Expectorants - Be a careful consumer when considering expectorants.  Though fancy ads portray these medications as having wonderful effects, many studies suggest that over the counter expectorants for increased mucus production with COPD simply don't work.
    • Mucolytics


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    Osadnik, C., McDonald, C., Jones, A., and A. Holland. Airway clearance techniques for chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews. 2012. 3:CD008328.

    Poole, P., Chong, J., and C. Cates. Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease. Cochrane Database of Systematic Reviews. 2015. 7:CD001287.

    Rubin, B. Secretion properties, clearance, and therapy in airway disease. Translational Respiratory Medicine. 2014. 2:6.

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