What happens to your body when humidity is low?

According to the Mayo Clinic, maintaining an indoor relative humidity between 30% and 50% is ideal for health. But when humidity levels drop below this range, your body can experience a range of uncomfortable and even harmful effects. So, what happens to your body when humidity is low?

Quick Summary

Low humidity draws moisture from your skin and mucous membranes, leading to dryness, irritation, and an impaired defense against airborne viruses and allergens.

Key Points

• Dries Skin and Hair: Low humidity pulls moisture from your skin and hair, causing dryness, itching, and brittleness.

• Increases Infection Risk: It dries out the mucous membranes in your respiratory tract, weakening your body's natural barrier against viruses and bacteria.

• Worsens Respiratory Issues: Dry air can irritate your sinuses, cause a sore throat and cough, and aggravate conditions like asthma and allergies.

• Contributes to Dehydration: Evaporation from your skin and breath increases in dry conditions, leading to subtle but chronic dehydration.

• Impacts Your Home: Beyond personal health, low humidity can also cause static electricity and damage wood furniture, floors, and other structural materials.

• Effective Solutions Exist: Using humidifiers, staying hydrated, and sealing air leaks are simple ways to combat the effects of dry air and maintain a healthier environment.

The Science of Dry Air

Humidity is the amount of water vapor present in the air. When the air is dry, it acts like a sponge, seeking moisture from its surroundings, including your body. This phenomenon, known as transepidermal water loss, is the root cause of many of the issues associated with low humidity, particularly during colder months when indoor heating further dries out the air.

Your body's initial defense mechanisms, such as mucous membranes, are the first to be affected. These membranes line your nasal passages, throat, and lungs, trapping bacteria, viruses, and irritants. In dry conditions, the mucus dries out, becoming less effective and leaving you more vulnerable to infections.

Impact on Your Skin and Hair

The effects of low humidity are often most noticeable on your skin and hair. The dry air pulls moisture from the outermost layers of your skin, leading to several issues.

Dry, Itchy, and Flaky Skin

• Dehydration: The moisture-stripping effect of dry air leaves skin feeling tight and dull. For individuals with conditions like eczema and psoriasis, low humidity can trigger flare-ups and worsen symptoms.
• Compromised Barrier: A dry skin barrier is a compromised one. This makes your skin more susceptible to external irritants and allergens, which can lead to increased redness and sensitivity.
• Premature Aging: Persistent dehydration can accelerate the appearance of fine lines and wrinkles as the skin loses its elasticity.

Brittle Hair

• Moisture Loss: Hair relies on a certain level of moisture to maintain its strength and shine. Low humidity saps this moisture, leaving hair brittle, frizzy, and prone to breakage and split ends.
• Static Electricity: The low moisture content in the air increases static electricity, leading to hair that is difficult to manage and full of flyaways.

Effects on Your Respiratory System

The constant inhalation of dry air puts significant strain on your respiratory system. Your body must work harder to warm and humidify the air you breathe before it reaches your lungs, leading to a cascade of problems.

• Irritated Sinuses and Throat: You may experience a scratchy, sore throat or irritated sinuses as the mucous membranes become parched. This can result in a dry cough, nasal congestion, and even nosebleeds.
• Impaired Mucociliary Clearance: The tiny, hair-like cilia that line your airways become less effective at moving mucus. This reduces your body's ability to clear trapped pathogens and irritants, making you more vulnerable to infections like the common cold and flu.
• Worsened Allergies and Asthma: Dry air can exacerbate existing respiratory conditions. For people with asthma, a sudden drop in humidity can trigger symptoms. While low humidity can minimize dust mite growth, the reduced effectiveness of mucous membranes can increase the risk of an allergic reaction to the remaining allergens.
• Higher Virus Transmission: Studies have shown that some viruses, including influenza, thrive in low-humidity environments, remaining airborne for longer and increasing the risk of transmission.

The Link to Dehydration and Fatigue

While sweating is the primary cause of dehydration in hot weather, dry air can cause significant fluid loss through less obvious means. The moisture evaporating from your skin and breath happens so quickly that you may not notice it, leading to subtle but chronic dehydration. This can result in general fatigue, lethargy, and headaches. Additionally, dehydration can affect cognitive function and physical performance.

Protecting Yourself and Your Home from Low Humidity

Fortunately, there are several effective strategies to mitigate the negative effects of low humidity. Balancing your indoor air is key to protecting your health and preserving your home's integrity.

Actions to take

1. Use a humidifier: This is one of the most effective ways to add moisture back into the air. Portable units are great for a single room, while whole-house systems can regulate humidity throughout your home. Read more on the benefits at Mayo Clinic: Humidifiers: Ease skin, breathing symptoms.
2. Stay hydrated: Continue to drink plenty of water, even if you don't feel as thirsty in cooler, dry weather. This helps replenish the moisture your body loses from evaporation.
3. Moisturize regularly: Use a high-quality moisturizer, especially after showering, to lock moisture into your skin. Hyaluronic acid and jojoba oil are particularly effective ingredients.
4. Seal air leaks: Check for drafts around windows and doors. Sealing these leaks can prevent dry outdoor air from entering and help maintain a consistent indoor humidity level.
5. Add houseplants: Certain plants like ferns and peace lilies naturally release moisture into the air through a process called transpiration.
6. Take warm, not hot, showers: While it may feel good, very hot showers can strip your skin of its natural oils. Warm showers are less harsh on your skin, and leaving the bathroom door open afterward allows some steam to circulate.
7. Dry laundry indoors: Air-drying your clothes indoors can be a simple, natural way to add moisture to the air.

Low vs. High Humidity: A Comparison

Feature	Low Humidity (Below 30%)	High Humidity (Above 60%)
Skin	Dry, flaky, itchy, prone to cracking.	Acne, breakouts, bacterial growth, and clogged pores due to excess sweat.
Respiratory	Dry sinuses, sore throat, increased vulnerability to airborne viruses, worsened asthma.	Airways can constrict, worsening asthma and trapping pollutants. Fosters mold growth.
Immune System	Impaired mucous membrane function and ciliary clearance.	Fosters the growth of mold and dust mites, increasing allergens.
Dehydration	Rapid evaporation from skin and breath can lead to subtle but chronic dehydration.	Excessive sweating, but inefficient evaporation, can lead to heat exhaustion.
Sleep	Dryness can cause snoring and interfere with comfortable breathing at night.	Can cause a stuffy feeling, leading to disrupted sleep and less restful REM sleep.
Home Damage	Wood shrinkage, warped floors, static electricity build-up.	Mold growth, peeling paint, warped wood, damp feeling, musty smells.

Conclusion

The air we breathe has a profound effect on our bodies. While often overlooked, low humidity presents a real and significant challenge to our general health, affecting everything from our skin and hair to our respiratory tract and immune system. By understanding what happens to your body when humidity is low, you can take proactive steps to protect yourself. By using simple tools like humidifiers and staying well-hydrated, you can maintain a comfortable indoor environment and support your body's natural defense mechanisms, especially during drier seasons. Don't let dry air sap your health; empower yourself with knowledge and simple solutions.

Frequently Asked Questions

What is the best humidity level for health?

The ideal indoor humidity level for both comfort and health is generally between 30% and 50%. This range minimizes the negative effects of both excessively dry and overly humid air.

Does low humidity make you sick?

While low humidity doesn't directly make you sick, it weakens your body's immune defenses. It dries out your mucous membranes, making it easier for airborne viruses and bacteria to cause infections like colds and flu.

Why do my lips get chapped when the humidity is low?

Your lips have very thin skin and lack the oil and sweat glands found on the rest of your body, making them especially susceptible to moisture loss. In low humidity, the air draws this moisture away quickly, causing them to become dry and chapped.

Can low humidity cause nosebleeds?

Yes, low humidity can cause nosebleeds. The dry air irritates and dries out the delicate membranes inside your nose, which can lead to cracking, bleeding, and increased susceptibility to infection.

How can I tell if my home's humidity is low?

Common signs of low indoor humidity include frequent static shocks, dry skin, chapped lips, a sore throat, cracked wooden furniture or floors, and a general feeling of being unwell indoors. A digital hygrometer can also provide an accurate reading.

Can low humidity affect sleep?

Yes, dry air can interfere with sleep. It can cause a dry throat and nasal passages, which may lead to snoring, coughing, and discomfort that disrupt your rest.

Do humidifiers help with dry skin?

Yes, using a humidifier adds moisture back into the air, which helps your skin retain its natural hydration. It can be a very effective way to combat dry, itchy, or flaky skin, especially in the winter.