Effects of Dry Air on the Body

Studies have shown that dry air has four main effects on the human body:

Breathing dry air is a potential health hazard which can cause such respiratory ailments as asthma, bronchitis, sinusitis, and nosebleeds, or general dehydration since body fluids are depleted during respiration.
  1. Skin moisture evaporation can cause skin irritations and eye itching.
  2. Irritative effects, such as static electricity which causes mild shocks when metal is touched, are common when the air moisture is low.
  3. The "apparent temperature" of the air is lower than what the thermometer indicates, and the body "feels" colder.

These problems can be reduced by simply increasing the indoor relative humidity.  This can be done through the use of humidifiers, vaporizers, steam generators, sources such as large pans, or water containers made of porous ceramics.  Even wet towels or water in a bathtub will be of some help.  The lower the room temperature the easier the relative humidity can be brought to its desired level.  A relative humidity indicator (hygrometer) may be of assistance in determining the humidity in the house.

Referring to item 4, a more detailed discussion is necessary.  While the indoor temperature as read from a thermometer may be 75°F, the apparent temperature may be warmer or colder depending on the moisture content of the air.  Apparent temperature can vary as much as 8°F within a relative humidity range of 10-80 percent (these limits are generally possible in a closed room).  Because of evaporation the human body cools when exposed to dry air, and the sense of coldness increases as the humidity decreases.  With a room temperature of 70°F, for example, a person will feel colder in a dry room than in a moist room; this is especially noticeable when entering a dry room after bathing.

For example, an apparent comfortable temperature can be maintained with a thermostat setting of 75°F with 20% relative humidity or with a 70°F setting with 80 percent humidity.  A relative humidity of 20% is common for homes without a humidifier during winter in the northern United States.

Dry air is known to trigger and exacerbate the discomfort of nasal congestion.  Nasal congestion is a condition that occurs when nasal tissues and blood vessels become swollen with excess fluid.  The excessive buildup of fluid can cause your nose to fell stuffy and make breathing difficult.  You are more susceptible to nasal congestion when you are in an indoor environment with low humidity.  www.MayoClinic.com recommends a humidifier to combat nasal congestion; the ideal humidity level is 30-50 percent.

  • Discolored Nasal Drainage - The United States National Library of Medicine reports that discolored nasal drainage is an ordinary symptom of nasal congestion and the condition is rarely sever.  Nasal discharge is often thick and creamy yellow or green in color.  Sponsored links such as Ask a Doctor: Mucus have doctors on staff who can answer your health questions in minutes.  www.Health.JustAnswer.com/Mucus
  • Headaches and Pain - The American Rhinologic Society reports that headaches often accompany nasal congestion because nasal structures swell and create intense facial pressure and pain.  The aching is often located on your forehead, cheeks and the corners of your eyes.
  • Coughing - Coughing is a frequent symptom of rhinorrhea.  When you suffer form nasal congestion, extra mucus may flow down your throat, triggering a cough reflex.  This problem is medically termed postnasal drip.  the condition generally worsens at night.
  • Fevers - Nasal congestion is often a symptom of common cold or influenza.  Hence, it is common to be afflicted with a fever when you suffer from nasal congestion.
References:
  1. Medicine Online: Sinus Infection - Sinusitis Journal of Clinical Investigation: Nasal Challange with Cold, Dry Air Results in Release of Inflammatory Mediators.
  2. MayoClinic.com: Nasal Congestion
  3. MayoClinic.com: Nasal Congestion
  4. National Institutes of Health: Nasal Discharge
  5. American Rhinologic: Headache and Sinus Disease