Cold-induced asthma occurs when cold weather triggers symptoms. Inhaling cold, dry air can cause the airways to tighten, making it harder to breathe.

Several treatments and preventive measures can help minimize the effects of cold air on a person with asthma.

This article describes why cold weather can worsen asthma symptoms and how to recognize when symptoms are being triggered.

Young male hiker with coffee by snowy forest river preventing cold-induced asthmaShare on Pinterest
Peter Amend/Getty Images

The nose and mouth typically warm and humidify the air before it reaches the lungs, and this makes it easier to breathe.

When the air is very dry and cold, as in the winter, it is more difficult for the body to warm.

When cold air hits the airways, the lungs react by tightening. Cold air contains less moisture, and breathing it in can dry out the airways. This can cause the airways to spasm, triggering an asthma attack, which can involve coughing.

According to the American College of Allergy, Asthma & Immunology, researchers once believed that the coldness of the air was the primary trigger of symptoms. However, more up-to-date research indicates that the dryness, rather than the temperature, is the culprit.

A person often finds that their symptoms worsen when they are being active outdoors — skiing, shoveling snow, or running, for example.

During exercise, it is more common to breathe through the mouth than the nose. Because the mouth does not warm air as well as the nose, a person is more likely to inhale colder air while exercising.

A combination of physical activity and breathing cold air can significantly worsen asthma symptoms.

Cold-induced asthma can cause symptoms that include:

These symptoms tend to develop shortly after a person is exposed to cold air outdoors. They usually go away after the person reaches a warmer environment.

However, an individual with more severe asthma may experience longer-lasting symptoms.

If a person has an asthma attack that is triggered by cold weather, they should first use their short-acting inhaler to loosen and open up the airways.

Typically, this inhaler contains albuterol, a beta agonist. A person should always carry their inhaler with them if they are going outdoors in colder temperatures.

Next, a person experiencing a cold-induced asthma attack should try to get to a warmer environment as quickly as possible.

After breathing in warmer air for several minutes, the airways should start to open up, and symptoms should reduce quickly.

If a person experiences these symptoms regularly, they should bring this up with their doctor. The doctor may prescribe further long-term treatments, such as a long-acting bronchodilator.

When exercise triggers asthma symptoms, the medical term for this is exercise-induced bronchoconstriction. To reduce this effect, a doctor may also prescribe medications called leukotriene receptor inhibitors.

For anyone with asthma, working to control symptoms and reduce the number of attacks can help prevent symptoms from developing in cold weather.

A person can take certain steps to prevent cold weather from triggering asthma symptoms.

Beyond taking medications, the following strategies can help:

  • Warming up for about 5–10 minutes before going outdoors. This could involve aerobic activity, such as dancing.
  • Using a short-acting inhaler 10–15 minutes before going outdoors. This can reduce the likelihood that cold air will cause the airways to narrow.
  • Wearing something that covers the mouth when outside. Covering the mouth with a scarf, for example, can warm the air on its way to the lungs.
  • Concentrating on breathing through the nose whenever possible. This also helps to warm the air before it reaches the lungs.

If possible, a person with cold-induced asthma should avoid going outdoors when temperatures reach 10°F or lower. Weather this cold is significantly more likely to trigger asthma symptoms.

Cold weather is a common asthma trigger, though the dryness of the air is more likely to cause problems than the temperature alone.

Engaging in physical activity while breathing in cold air can further worsen asthma symptoms.

If a person cannot manage their asthma symptoms well with preventive measures and prescribed medications, such as short-acting inhalers, they should consult a doctor.

The doctor can recommend further treatments to prevent symptoms from growing more severe.