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How Humidity Can Impact Your Lungs

Learn About Humidity's Effect on Your Lungs and How to Prevent Flare-Ups

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Dayton Respiratory Center

Sep 01 2022

5 mins read

After sitting outside on a warm, sunny day, you can expect to feel hot and sweaty. But sometimes, you might also feel suffocated — like you can't take in a full, deep breath.


The feeling of suffocation is caused by an increase in humidity.

If you live in a humid climate, you're probably used to the sticky feeling you get when you're outside. But did you ever notice how humidity affects your lungs?

Humidity can make breathing more difficult — especially for people with preexisting lung conditions.

Let's talk about humidity, how it affects your lungs, and how you can prevent humidity-related flare-ups.

What is Humidity?

The air we breathe contains water vapor. The amount of water vapor in the air is called humidity.

Hotter air can hold more water vapor than colder air. So, hotter air means more humidity.

Why Does Humidity Make You Feel Hotter?

‎When it's hot, you sweat; it's your body's mechanism to maintain its temperature. Your body tries to cool itself down by evaporating the sweat on your skin.

But if the air is already saturated with water vapor, there's nowhere for the sweat to evaporate. So, you just end up feeling hot and sticky.

How hot you feel depends on the relative humidity.

What is Relative Humidity?

Relative humidity is the current amount of water vapor in the air compared to the maximum amount of water vapor that could be present at the given temperature.

The higher the relative humidity, the hotter the temperature feels.

The Effect of Humidity on Temperature|NWS

For example, a temperature of 94 degrees Fahrenheit feels like 97 degrees at 40% relative humidity. But that same temperature feels like 129 degrees Fahrenheit at 80% relative humidity.

How Much Humidity Makes You Uncomfortable?

The standard, comfortable level of relative humidity ranges between 30%-60%.

Relative humidity greater than 60% can make you feel uncomfortably hot.

In addition, low relative humidity (below 30%) might also make you uncomfortable for other reasons. The air is dry, meaning it has significantly less water vapor. Low humidity causes your body to lose moisture, leading to dry nasal passages, sore throat, and dry skin.

How Does Humidity Affect Your Breathing?

1. Decreases Oxygen Availability

Humid air is dense due to the presence of moisture. Dense air increases air resistance, so your lungs have to work harder to breathe. Why?

As water vapor concentration increases, oxygen concentration decreases. Our lungs must put in more effort to meet the body's oxygen requirement.

2. Increases the Need for Temperature Regulation

High humidity makes it difficult to stay cool by sweating. This means your body must work harder to maintain a normal temperature.

To regulate its temperature, your body increases blood flow and respiration, which further taxes your lungs.

3. Constricts Airways

Inhaling humid air activates certain nerve fibers that cause your airways to constrict. Constricted airways restrict airflow, making it difficult to breathe.

4. Triggers Allergic Reactions

Humidity can trap allergens like mold, dust mites, pollen, and smoke. The presence of allergens in the air can trigger an allergic reaction. This can agitate both your lungs and your sinuses, making it difficult to breathe.

Can Humidity Aggravate Asthma and COPD?

Yes. Humidity can aggravate lung conditions like asthma and COPD.

Asthma and COPD (Chronic Obstructive Pulmonary Disease) are medical conditions that make it difficult to breathe normally.

If you have asthma or COPD, you may have noticed that your symptoms worsen when the air is more humid. For example:

  • If you have COPD
    • You already use most of your energy to breathe. Under humid conditions, your body requires even more energy to stay cool. Regulating your body temperature makes breathing even harder, aggravating your COPD.
  • If you have asthma
    • You may experience an allergy-induced asthma attack. Dust mites and mold flourish in humid conditions. As the air is stagnant during humid conditions, allergens and moisture can agitate and constrict your airways.
    • A study has also shown that humidity induces bronchoconstriction —constriction of airways— in asthma patients.

How to Manage Humidity to Prevent Flare-Ups

Follow the steps below to prevent a flare-up during high humidity:

  1. Stay indoors
    1. Keep the windows shut and the air conditioner running. You can open your windows at night — when the humidity levels are low — to let in some fresh air.
  2. Use a dehumidifier
    1. Dehumidifiers help to remove excess moisture in the air.
  3. Stay hydrated
  4. Avoid intense exercise and strenuous activities
  5. Keep track of the humidity levels
    1. Check the humidity levels in your area before heading out. Avoid going outside when the temperature and humidity levels are high.
  6. Wear loose clothing
    1. Wear light-colored, loose-fitting clothes and a hat when you go outdoors. This ensures better air circulation and less heat absorption.
  7. Always keep your medication handy
    1. Always make sure to bring your inhaler or other breathing-related medications. This is especially important if you have a preexisting lung condition.


Humidity can make anyone feel suffocated in the summer.

Humidity makes the air denser and reduces the concentration of available oxygen. As a result, your lungs must exert more energy to meet your body's oxygen and temperature requirements.

You should be especially careful of humidity if you have a lung condition. If you have asthma or COPD, track the humidity levels in your area and take necessary precautions to avoid a flare-up. Always keep your medications handy and consult your doctor if symptoms worsen.

Humidity is part of nature, and we cannot control it. But a few simple steps will ensure you stay comfortable and healthy during the hot summer days.

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