Why some people cough more in summer

Not everyone enjoys summer equally – while the heat and longer days may be bliss for some, the humidity can wreak havoc with others' health.

Have you ever wondered how it's possible to develop an annoying cough during summer? It largely depends on the humidity levels in your area.

Unexpected triggers

We often assume that humidity soothes our airways and relieves coughing, while dry, dusty air is a specific a trigger for coughing. This is, however, not always the case.

Heat and humidity can make it harder to breathe, especially if you suffer from asthma, allergies or chronic obstructive pulmonary disease (COPD).

"When you have an increase in humidity, the humidity itself can trigger asthma," says asthma expert Susan S Laubach, MD, an associate physician at the Allergy & Asthma Medical Group and Research Center in San Diego.

And it is not only the physical humidity that can lead to coughing. Warm temperatures create the perfect conditions for the breeding of allergens such as dust mites, which can trigger allergy symptoms like coughing.

When does humidity trigger a cough?

According to Dr Don Hayes, medical director of the Lung and Heart-Lung Transplant Program at the Nationwide Children’s Hospital in the USA, cold air can cause constriction of the airways in those suffering from asthma.

However, it is not fully understood why higher temperatures and humidity also trigger coughing.

“The effects that temperature increases have on airways functions are generally overlooked. We know very little about the mechanisms that cause symptoms when asthmatic patients are exposed to hot, humid air.”

But a study conducted by Dr Hayes and his colleagues showed that breathing hot, humid air triggered an immediate increase in airway resistance in the study subjects who had mild asthma.

Those with healthy lungs only had a very small response to the humid air. While the mechanisms of these results weren’t fully understood, the same research group also researched airway sensory nerves. It turned out that these nerves were activated by an increased temperature in the chest, causing defence reflexes such as coughing and bronchitis, said Dr Hayes.

Curb your cough this summer

If you are prone to asthma and allergies during summer, there are ways to control coughing and other allergy symptoms caused by humidity and rising temperatures:

  • Adapt your medication according to the temperature. Speak to your doctor if warmer weather triggers your cough.
  • Follow a healthy lifestyle to keep your immune system in tip-top shape and prevent secondary infections.
  • Keep your house free of pet dander, mould, dust mites or other possible allergens that may flourish in warmer temperatures.
  • Visit your doctor immediately if your symptoms become worse or if you experience shortness of breath, dizziness or lightheadedness when coughing. 

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