For people with respiratory diseases, including IPF, weather can cause worse symptoms, also known as flare-ups. This can happen if it’s too hot outside, or too cold, or if it’s too humid or not humid enough. Air pollution can also wreak havoc on your lungs. Any of these triggers can worsen breathlessness, cough, or fatigue.
Cold Air
Cold air tends to be drier and denser, and when you inhale, it can trigger cough, throat irritation, and a sensation of chest tightness. In addition, your lungs may produce more mucus, which can also worsen symptoms.
“People often unconsciously breathe faster and more shallowly [when the air is cold], which can heighten the feeling of breathlessness,” says Dr. Rice. “Population data show that mortality from pulmonary fibrosis is highest in winter, even after excluding obvious infections, suggesting that cold, infections, and possibly indoor exposures all play a role.”
Heat and Humidity
Similarly, when summer rolls around, hot, humid weather can also have a negative impact on your breathing. High heat, particularly when combined with humidity, can make it more difficult for oxygen to reach the lungs. Humid air is denser, which makes it more difficult for your lungs to draw it in. “It feels ‘heavy,’ and even healthy people require more effort to breathe in hot, humid conditions,” says Rice. “For someone with IPF, whose lungs are already stiff, this extra work can translate into shortness of breath, fatigue, and the need to stop and rest.”
In addition, she adds, high humidity also provides an ideal environment for mold and other allergens.
“Studies have found that higher temperatures and higher heat index, which accounts for humidity, increase emergency visits and hospitalizations for chronic lung diseases and risk of respiratory failure,” says Rice. “In my own research involving patients with COPD, patients report worse breathlessness when exposed to higher temperatures, including summer heat and indoor exposure to heat during the winter.”
Heat can also trigger inflammation in the airways, which will aggravate symptoms like coughing and shortness of breath.
Some early research in mice suggests that exposure to high temperatures can damage DNA and cells in the lungs and potentially contribute to IPF progression.
Air Pollution
In addition, high temperatures can also increase levels of air pollution, which may contribute to IPF flare-ups.
“Air pollution can trigger respiratory symptoms and cause exacerbations of many chronic lung diseases, including IPF,” says Jamie Garfield, MD, a medical spokesperson for the American Lung Association and a professor of thoracic medicine and surgery at the Temple Lung Center at Temple University Hospital in Philadelphia. “Air pollution or particle pollution and poor air quality or ozone can irritate your lungs. Chronic exposure to both particle pollution and ozone can cause coughing, chest tightness, and shortness of breath.”
She noted that in some patients with IPF, exposure to air pollution can increase oxygen requirements and reduce lung function. “It may also exacerbate otherwise stable disease,” says Dr. Garfield.