Moisture is both a blessing and a curse.  When you have just what you need your health and the health of your buildings is ensured.  But when you have too much, your buildings can fail in many ways that can not only damage the structure but affect your health and well-being.  

When moisture is at appropriate levels, we are not even aware of it.  It just does its job.  But when it gets out of control it always leaves a calling card in mostly obvious places: rotting wood, rusting metal, moldy surfaces, condensation on windows, peeling paint, and spalling (surface deterioration) masonry. 

Depending on your sensitivities, you may experience dryness in your nose and respiratory system when moisture is insufficient, or experience allergic reactions from the molds and other allergens produced by organisms that are encouraged by too much moisture.

Sometimes moisture's calling card is in a hidden crawlspace, in a wall cavity, under a carpet or under a cardboard box sitting on a basement floor and we have to do some serious exploring that involves turning things over and opening up places so we can get a better view.