Chest Heaviness in Humid Weather


Humidity can be defined as the amount of water or moisture present in the air. When the media mentions humidity levels, they are talking about "relative humidity." Higher humidity levels are typically related to higher temperatures and are at their highest during the summer. Humidity levels is the ratio of the amount of water in the air to the maximum amount of water the air can hold at the current temperature. When compared to cold air, hot air can store more moisture. So, on a hot day, a relative humidity level of 70% will seem much "wetter" than the same humidity level on a cold day. According to the National Weather Service, humidity levels of less than 55% during the hot summer months are "pleasant." Anything between 55% and 65% humidity feels "sticky," and anything above 65% feels "oppressive”. Humidity levels of 65% and higher are likely to be an irritating type trigger for many asthmatics.1

Effects of humidity on Asthma

Why is it difficult to breathe in humid weather?1

  • On humid days with a lot of moisture in the air, people's asthma symptoms may get worse. This is especially true when working out in humid weather.
  • Humidity levels above 50% may contribute to asthma symptoms in a variety of ways.
  • Humidity can raise the quantities of various chemicals in the air that irritate the bronchial tubes, such as pollen and pollutants, and this can directly irritate the airways.
  • Asthma symptoms can be triggered by high humidity, including chest tightness, coughing, and wheezing.

The effects of humidity on a person's lungs have been studied on a small scale.3 Six people with asthma and six people without asthma were assessed for airway resistance, which is a measure of how easy it is to breathe. People with asthma showed a 112 per cent increase in airway resistance after 4 minutes of exposure to hot, humid air (49°C and 75–80% humidity), compared to a 22 per cent rise in airway resistance in the healthy group.3 Bronchoconstriction can develop when hot, humid air triggers C fibres in the airways, which are sensory nerve fibres.8 The stimulation of C fibres can restrict the airways and cause coughing, making breathing harder. 

Symptoms of Asthma

Asthma symptoms include:

  • Inflammation of the airways.
  • Thick mucus that clogs the airways.
  • Muscles constrict and tighten around the airways.

Your airways become smaller or narrower as a result of the swelling, congestion, and muscular tension. This makes it more difficult for air to flow freely through your airways, making breathing more difficult. Asthma symptoms, sometimes known as an asthma episode, flare-up, or attack, result from this and could occur at any time.9 Mild asthma symptoms may last only a few minutes, whereas severe asthma symptoms might linger for hours or even days. Breathing becomes difficult and uncomfortable as if breathing through a cotton-stuffed straw.

The following are some of the most common signs that you are experiencing an asthma flare-up may be in the beginning stages of an asthma attack:9 

  • Breathing problems
  • Cough
  • Tightness or pain in the chest
  • Sneeze (a whistling sound when you breathe)
  • Asthma symptoms keeping you up at night
  • A decrease in the reading on your peak flow metre (if you use one) 

It is important to understand that these symptoms are not the same for everyone. You could experience a single symptom or a number of them.

Managing the effects of humid weather

First and foremost, all those suffering from asthma should have a written action plan to help with symptom management. Refer to your action plan as soon as you see any symptoms. Here are a few other ways in which health can be managed in humidity.5

  • Before heading outside, check the air quality on a daily basis.
  • Determine the outside temperature and relative humidity. 
  • Check the pollen and mould levels in your area. When any of those elements are high, your best chance is to stay as much as possible indoors in the air conditioning. Exercise inside or during the day when the temperature and humidity are lower.
  • Take your asthma meds as directed. Keep your quick-relief or rescue inhaler with you at all times in case symptoms arise.

Controlling indoor humidity

  • Switch on Air Conditioning and close all windows
  • Use a dehumidifier7
  • Ensure your house has good insulation
  • Turn on the fan in the bathroom

Preventing humid weather from triggering asthma symptoms

  • Avoid going outdoors on humid days
  • Always keep an inhaler with you
  • Don't exercise outdoors on humid days
  • Drink lots of water
  • Wear loose clothing

Asthma Treatments

Long-term medications


They are the most potent and effective anti-inflammatory drugs on the market right now. When starting long-term therapy, short courses of oral systemic corticosteroids are frequently utilised to acquire quick control of the condition; long-term oral systemic corticosteroids are used for severe persistent asthma.4,10


To treat mild asthma, you take this bronchodilator in pill form every day. Theophylline relaxes the airways and reduces lung irritation reactions. It can help with asthma symptoms at night. Regular blood tests may be required to ensure that you are receiving the correct dose. Insomnia and gastric reflux are two possible side effects of theophylline.11

Leukotriene modifiers

These drugs work by inhibiting the actions of leukotrienes, which are immune system molecules that induce asthma symptoms. For up to 24 hours, leukotriene modifiers can help prevent symptoms.12 Here are several examples:

  • Montelukast 
  • Zafirlukast 
  • Zileuton 

Montelukast has been related to psychological symptoms such as agitation, violence, hallucinations, depression, and suicidal ideation in rare situations. If you have any of these side effects, contact your doctor immediately.

Quick-relief medications

These asthma drugs relax the airway muscles, allowing the lungs to open up. They're also known as rescue drugs since they can help with worsening symptoms or stop an asthma attack in its tracks. They are effective for four to six hours and start acting within minutes. 

To prevent shortness of breath and other asthma symptoms, some people use a quick-relief inhaler before exercising. Jitteriness and palpitations are two possible adverse effects.3,6,7

Medications for immediate relief include:

  • Albuterol 
  • Levalbuterol

If your symptoms are mild and infrequent, or if you have exercise-induced asthma, you may be able to manage your symptoms with just one of these medications. Most persons with chronic asthma, on the other hand, require an inhaled corticosteroid or another long-term management prescription.

If you need to use your inhaler more frequently than your doctor suggests, your asthma isn't under control, and you're putting yourself at risk for an asthma attack.


Chest tightness and asthma symptoms are exacerbated by humidity due to the high water content in the air. This causes Bronchoconstriction and results in the need for asthma symptoms to be regularly monitored. The key to keeping your symptoms under control during humidity is to keep track of your symptoms and side effects and alter your therapy accordingly. 

Know when to change your meds, when to go to the doctor, and how to spot an asthma attack. If your doctor has prescribed a peak flow metre to assess how well your lungs are doing, follow the instructions carefully. Even if you're feeling fine, stick to your drug regimen and keep track of your symptoms until you see your doctor.


  1. Watson S. Humidity and asthma [Internet]. Healthline. 2018 [cited 2022 Jul 5]. Available from:
  2. Weather [Internet]. Asthma + Lung UK. [cited 2022 Jul 5]. Available from:
  3. Humidity and asthma: What’s the link? [Internet]. 2019 [cited 2022 Jul 5]. Available from:
  4. What are asthma symptoms? [Internet]. [cited 2022 Jul 5]. Available from:
  5. Bottrell J. Asthma and air conditioners: What you should know! [Internet]. 2019 [cited 2022 Jul 5]. Available from:
  6. Watkins J. 3 ways air conditioning improves asthma symptoms [Internet]. McWilliams & Son. McWilliams & Son Heating and Air Conditioning; 2017 [cited 2022 Jul 5]. Available from:
  7. Wilder A. How can A dehumidifier help with asthma treatment? [Internet]. 2020 [cited 2022 Jul 5]. Available from:
  8. Wells D. Bronchoconstriction [Internet]. Healthline. 2017 [cited 2022 Jul 5]. Available from:
  9. Asthma [Internet]. [cited 2022 Jul 5]. Available from:
  10. Corticosteroids [Internet]. [cited 2022 Jul 5]. Available from:
  11. Theophylline: Various toxicities: case report. React Wkly [Internet]. 2015 [cited 2022 Jul 5];1547(1):257–257. Available from:
  12. Zacharek MA, Birkeland AC. Leukotriene Modifiers. In: Practical Medical and Surgical Management of Chronic Rhinosinusitis. Cham: Springer International Publishing; 2015. p. 305–11.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Ankita Thakur

Postgraduate Degree, MSc. Biotechnology and Management, University of Glasgow
Experienced as a Healthcare Management Intern and Healthcare Writer.

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