Some types of heating systems overdry the air. This can cause discomfort. Moisture may be added to the air in the winter months by using a humidifier. It is difficult to obtain the optimum humidity level in a home. At this percentage, occupants feel comfortable and most moisture problems can be avoided.
Skin feels damp or clammy.
Upholstery, walls, etc. Odors may signal rot or mildew. Wood may show signs of moisture damage. Windows may fog on the outside. Skin feels dry and itchy.