The imminent approach of summer will bring seasonal changes that can affect people with chronic obstructive pulmonary disease, but the truth is that there is no good season for COPD patients. Factors associated with both warm and cold weather can exacerbate COPD and cause problems for those living with it.
We know that environmental conditions, including outdoor and indoor air pollution, can contribute to causing COPD. The inhalation of irritating particles can cause the mucus glands in the bronchi to produce more mucus than normal, leading to thickening and inflammation of the bronchi walls.
But air pollution also is one of the common causes of COPD exacerbations, in which the airways become blocked and COPD symptoms suddenly get worse. Exacerbations can cause infection in the airways and lead to hospitalization, so it is important for patients to be able to recognize symptoms, which may include:
- Worsening of a stable condition;
- Increased difficulty breathing;
- Increased wheezing, coughing, mucus production;
- Change in the appearance of mucus;
- Chest tightness;
- Irritability or change in personality;
- Fluid retention;
- Forgetfulness, confusion, slurring of speech, sleepiness.
In addition to air pollution, changes in the weather and air temperature can trigger or worsen COPD symptoms. Both hot and cold air cause problems,[3,4] because each type of weather brings its own set of breathing irritants.
Spring/Summer and Hot Weather
COPD symptoms can flare on days of high heat and humidity, partly because these conditions often are accompanied by high levels of smog. COPD patients should try to stay indoors in an air-conditioned environment on hot, humid days. High temperatures can cause dyspnea and exhaustion as the body works harder to breathe and maintain a normal body temperature. Warm air also can cause the airways to constrict, possibly causing bronchospasms. Humidity causes shortness of breath because humid air contains more moisture and less oxygen, making it heavier and harder to breathe.
When hot, humid air is accompanied by outside allergens common to warm seasons, COPD patients can have even more difficulty breathing. According to the Asthma and Allergy Foundation of America, one out of five people in the United States have asthma and allergies, including those that also may have COPD, and many people have multiple allergies. "Outdoor allergies (also called "seasonal allergic rhinitis" (SAR), "hay fever," or "nasal" allergies) occur when allergens that are commonly found outdoors are inhaled into the nose and the lungs causing allergic reactions. Examples of commonly inhaled outdoor allergens are tree, grass and weed pollen and mold spores."
Any substance that causes an allergic reaction can exacerbate COPD symptoms because exposure to an allergen typically narrows the airways and increases mucus production, making it harder to breathe. However, there is no clear connection between allergies and COPD, although many believe that patients with compromised airways caused by allergies or asthma are at increased risk for COPD and some believe allergies and asthma are the early stages of COPD. Even so, current COPD treatment guidelines do not include strategies for the management of allergies in COPD patients.
Recent research out of Johns Hopkins University found that COPD patients with allergic disease have higher levels of respiratory symptoms and are at higher risk for COPD exacerbations. In a press release announcing results of the study, Nadia N. Hansel, MD, MPH, associate professor of medicine at the Johns Hopkins Asthma & Allergy Center and one of the researchers on the project, commented, "Although allergic sensitization and allergen exposure are known to be associated with impairments in lung function, the effects of allergic disease on respiratory symptoms in COPD patients has only recently been studied." She added that the study's findings suggest that treatment of active allergic disease or avoidance of allergy triggers may help improve respiratory symptoms in COPD patients and that more studies of the relationship between allergic disease and COPD are needed.
Fall/Winter and Cold Weather
Allergy problems are not limited to the warm months. When the weather gets cold, people--including COPD patients--spend more time indoors, where a whole new set of allergens may await them. Common indoor allergies (also called perennial allergic rhinitis or PAR) include dust/dust mites, dirty carpets/rugs, pet dander, mold, fumes, and fragrances/perfumes. It is estimated that 10 million people are allergic to cat dander, the most common pet allergy.[6,7]
Experts suggest that COPD patients should try to eliminate exposure to and reduce conditions that promote indoor allergens, along with hobbies or home improvements that produce may produce dust and contaminate the air with particle irritants.
Just as in the summer months, air temperature also can affect COPD symptoms in the winter. Cold air and strong winds may worsen COPD symptoms, including shortness of breath, cough and mucus/phlegm production. Frigid air can be hard to breathe and wind resistance requires more effort to move, both of which may cause fatigue. Experts suggest that COPD patients try to breathe through the nose, covered by a scarf or mask, on cold days; this will help to warm air before it reaches the lungs.
Cold weather also brings cold and flu season, which can be very dangerous for COPD patients. According to an article published in the International Journal of Chronic Obstructive Pulmonary Disease, "Viral infections including influenza, respiratory syncytial virus (RSV), and many other viruses are important causes of exacerbations, excess morbidity and mortality in COPD."
In the damaged lungs of COPD patients, colds and the flu can escalate quickly into infection. Bacteria contribute to inflammation of the lungs and often can be found in the lungs of COPD patients even when their conditions are stable. Studies have shown that 29% of patients with stable COPD and 54% of patients experiencing a COPD exacerbation have significant levels of bacteria.
Viruses also cause COPD exacerbations. Studies have shown that viral infections precede up to 65% of exacerbations, COPD exacerbations are higher during influenza season and that much of the excess mortality seen during flu season occurs in COPD patients.
With statistics like the above, it is clear that preventive measures during cold and flu season are extremely important for COPD patients. Washing the hands is a primary but extremely effective way to help prevent upper respiratory infections; everyone, especially COPD patients, should wash their hands with soap and water after eating and after being outside the home.
To reduce the risk of exacerbations, it is very important for COPD patients to stay up to date on preventive vaccinations, especially those for influenza and pneumococcal disease. They should get the flu vaccine 6 weeks before the flu season begins and discuss with their doctors the possible need for further vaccinations against tetanus, diphtheria, pertussis; and in some cases, shingles and hepatitis B.[3,12,13]
Additionally, COPD patients should try to avoid situations where they may come into contact with sick people, such as travel, airplanes, shopping malls, and exposure to school age children.
To paraphrase Mark Twain, there's not much we can do about the weather. But respiratory clinicians can be aware of the way weather and seasonal changes may affect their COPD patients and offer education to help them prevent exacerbations and promote life quality.
1. What is Chronic Obstructive Pulmonary Disease (COPD)? American Thoracic Society. http://www.thoracic.org/clinical/copd-guidelines/for-patients/what-is-chronic-obstructive-pulmonary-disease-copd.php
2. COPD and Exacerbations. COPD Digest. Vol. 8, No. 4, 2012, pg. 20
3. Chronic Obstructive Pulmonary Disease-Complications. University of Maryland Medical Center. http://www.umm.edu/patiented/articles/how_serious_chronic_obstructive_lung_disease_000070_5.htm
4. McCoy, K. How Weather Can Affect Your COPD. http://www.everydayhealth.com/copd/weather-can-affect-copd.aspx
5. Preparing for Seasonal Changes is Key to Managing COPD. COPD Digest. pg. 12, Vol. 8, No. 3, 2012.
6. Allergy Facts and Figures. Asthma and Allergy Foundation of America. http://www.aafa.org/display.cfm?id=9&sub=30#prev
7. Jovinelly J. COPD and Allergies: Avoiding Pollutants and Allergens. Healthline. http://www.healthline.com/health/copd/allergies#1
8. Chronic obstructive pulmonary disease. Tri Health. http://trihealth.adam.com/content.aspx?productId=10&pid=10&gid=000070
9. Allergic Disease Worsens Respiratory Symptoms and Exacerbations in COPD. American Thoracic Society. May 2013 press releases. http://www.thoracic.org/media/press-releases/journal/articles/May%202013.php
10. Campagna, A. What You Should Know About Indoor Air Pollution, COPD Digest, Vol. 9, No. 1, 2013.
11. Wesseling, G. Occasional review: Influenza in COPD: pathogenesis, prevention, and treatment. Int J Chron Obstruct Pulmon Dis. 2007 March; 2(1): 5-10. Published online 2007 March, accessed 5/15/2013 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2692115/
12. Weissler, JC. Infection and COPD. Lung Health Professional Magazine, Vol. 3, No. 3, 2012, pg. 16.
13. Yawn, BP. Immunizations for Adults with COPD. Lung Health Professional Magazine. Vol.3, No. 4, 2012, pg. 28.
Judi Biederman is on staff at ADVANCE.