Humidifiers: Air moisture eases skin, breathing symptoms

Humidifiers can ease problems caused by dry air. But they need regular maintenance. Here are tips to ensure your humidifier doesn't become a household health hazard. By Mayo Clinic Staff

Dry sinuses, bloody noses and cracked lips — humidifiers can help soothe these familiar problems caused by dry indoor air. Humidifiers can also help ease symptoms of a cold or another respiratory condition.

But be cautious: Although useful, humidifiers can actually make you sick if they aren't maintained properly or if humidity levels stay too high. If you use humidifiers, be sure to monitor humidity levels and keep your humidifier clean. Dirty humidifiers can breed mold or bacteria. If you have allergies or asthma, talk to your doctor before using a humidifier.

What are humidifiers?

Humidifiers are devices that emit water vapor or steam to increase moisture levels in the air (humidity). There are several types:

  • Central humidifiers are built into home heating and air conditioning systems and are designed to humidify the whole house.
  • Ultrasonic humidifiers produce a cool mist with ultrasonic vibration.
  • Impeller humidifiers produce a cool mist with a rotating disk.
  • Evaporators use a fan to blow air through a wet wick, filter or belt.
  • Steam vaporizers use electricity to create steam that cools before leaving the machine. Avoid this type of humidifier if you have children; hot water inside this type of humidifier may cause burns if spilled.

Ideal humidity levels

Humidity is the amount of water vapor in the air. The amount of humidity varies depending on the season, weather and where you live. Generally, humidity levels are higher in the summer and lower during winter months. Ideally, humidity in your home should be between 30 and 50 percent. Humidity that's too low or too high can cause problems.

  • Low humidity can cause dry skin, irritate your nasal passages and throat, and make your eyes itchy.
  • High humidity can make your home feel stuffy and can cause condensation on walls, floors and other surfaces that triggers the growth of harmful bacteria, dust mites and molds. These allergens can cause respiratory problems and trigger allergy and asthma flare-ups.

How to measure humidity

The best way to test humidity levels in your house is with a hygrometer. This device, which looks like a thermometer, measures the amount of moisture in the air. Hygrometers can be purchased at hardware stores and department stores. When buying a humidifier, consider purchasing one with a built-in hygrometer (humidistat) that maintains humidity within a healthy range.

May. 18, 2013 See more In-depth