Look for cracks in walls, sweating windows, pooled water, peeling paint and mold.  You may need to regulate humidity levels in your home.

Can you hear water dripping?  Is your furnace or air conditioner making strange sounds?  Your heating or cooling system may be due for a Tune-up.  Is your furnace too loud?  Your ductwork may be leaky or the wrong size for your home.

Smell mildew?  You may have too much humidity.  Sneezing?  You may have a dust, pollen, or mold problem.  If you can still smell your cooking after four hours, your house is not adequately ventilated.

Do you feel any drafts?  You may have leaks near windows, doors, attic accesses or dryer vents or your heating and cooling system airflow may be sized improperly.  Is your skin dry and flaky?  Do you get static shocks?  Your house may be too dry and require humidification.