How Summer Heat and Allergens Affect Asthma

If you have asthma, summer can be a difficult season. Heat and humidity can affect your airways, with hot air causing them to tighten and narrow. This can trigger wheezing, breathing difficulty (such as shortness of breath), and other symptoms, increasing the likelihood of asthma attacks.

Likewise, humid air is not only heavy and hard to breathe (especially in the heat), but it traps irritants and allows allergens such as dust mites and mold to thrive . This diminishes air quality and often triggering asthma symptoms.

This effect occurs regardless of the type of asthma you have. If you have allergic asthma, you may find managing your asthma to be especially challenging in the summer. The same is true if you have exercise-induced asthma and tend to be more active outdoors during the summer.

Causes of Summer Asthma Symptoms

Although asthma symptoms tend to be most common in fall and winter, summer presents some unique risks.

Heat: The mere fact that you have asthma means your lungs are especially sensitive to extreme heat, and so breathing in hot air can aggravate your airways and trigger symptoms. What’s more, if you become dehydrated, you will naturally breathe more rapidly than normal, which also can play a role in setting off symptoms.

Humidity: Humid air is heavy air, so it’s harder to breathe, especially when it’s also hot. In addition, moist air traps lung irritants, such as pollen, and encourages mold and dust mites (indoors) to thrive.

Ozone: Ozone (or the main component of smog) is a product of atmospheric chemicals and sunlight. Although more research is needed to discount statistical uncertainty and better assess adult lung function in response to different levels of exposure, many researchers believe this pollutant can exacerbate asthma, especially in children. This is based on studies that show lung function worsens in the days after ozone levels peak, affecting people with asthma and even people without it.

Summer allergens: If you have allergic asthma and are triggered by certain allergens that are especially prevalent in June, July, and August, it stands to reason you’re more likely to have asthma attacks during those months.

• March through June: Tree pollen high
• May through early June: Grass pollen high
• June: Outdoor mold spores peak and decrease after the first frost
• August through the first frost: Weed pollen high (daily peaks around noon)

Smoke: From a small campfire to a raging wildfire, you’re more likely to be exposed to smoke in the summer months. Smoke carries fine particulate matter that can get into your airways and have a major impact on asthma.

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Managing Summer Asthma

If you have a history of worsened asthma in the summer, work with your asthma healthcare provider to devise a seasonal action plan, which may include incorporating additional medications and/or lifestyle measures into your overall management measures.

It will be key to head into summer with your asthma well under control. It is not under control if:

• You use a rescue inhaler more than twice a week.
• Asthma symptoms interrupt sleep more than twice a month.
• You need a new rescue inhaler more than twice a year.

Follow your asthma action plan, try to avoid triggers, and stick to the asthma medication regimen prescribed by your healthcare provider. These steps may include taking a daily asthma controller medication to prevent asthma symptoms and rescue medications to treat acute symptoms.

Prevention

Steering clear of allergens altogether may be difficult, especially if you enjoy being outside in the warm weather. In addition to following your prescribed treatment plan, this may involve taking some special precautions in the summertime:

• Check pollen counts for your area. You can get this information from local weather forecasts, on TV or online, from weather or pollen-count smartphone apps, or from the National Allergy Bureau’s website.
• Stay indoors on bad days. During extreme heat and humidity, high pollen or wildfire smoke days, thunderstorm warnings, and ozone alert days (and a few days afterward), limit outdoor activities as much as possible.
• Shower after outdoor activities. Wash off pollen or other irritants you may have tracked indoors.
• Don’t let dust accumulate in your home. Pollen can get intermingled with dust and lie around for long periods. Keep windows closed, vacuum often, and dust (perhaps while wearing a mask) to avoid inhaling these allergens/irritants.
• Use a dehumidifier and air conditioner. Reducing the humidity in the air and keeping the temperature cool (but not freezing cold) can make it easier to breathe in general as well as help prevent the growth of mold. Make sure to clean and change air filters regularly.
• Consider immunotherapy (allergy shots). The National Institutes of Health recommends subcutaneous immunotherapy (SCIT) for some people over 5 years who have allergic asthma. Ask your healthcare provider if allergy shots might be appropriate for you.

Summary

The summer months can be difficult for those who suffer from asthma. Not only are summer allergens, like mold and pollen, plentiful during the hot and humid season, but the heat and humidity on their own can trigger asthma symptoms. The hot air can aggravate the airways and cause dehydration, while the humidity tends to trap lung irritants and makes it harder to breathe. Air pollutants, like ozone and smoke, may also have an impact.

It is advised that people with asthma devise a seasonal asthma plan with their healthcare provider that may include checking pollen counts, staying indoors or avoiding exercises that make it harder to breathe on bad days, dusting indoors, using a humidifier and air conditioner, and allergy medications and/or shots if necessary.