Aggravated Allergy/Asthma Symptoms
If you suffer from allergies, asthma, or other respiratory issues, then you are going to suffer greatly as a result of low indoor air quality. There are, of course, certain times of the year when your allergies will be worse than others. However, if you have persistent flareups, especially if those seem to develop when you are within your own home, then you likely have too high a concentration of airborne pollutants therein. An air filtration system can help to alleviate such symptoms, as can UV air purifiers.
Dry, Itchy Skin, Sore Throats, Etc.
If the air in your home is too dry, then the various objects, including your own body, within that home will feel the effects of this problem. Your skin, throat, and nasal passages may dry out, and your wooden floorboards/furniture may split or crack. You may also notice an uptick in the frequency with which annoying static shocks strike. Consider using a whole-house humidifier to overcome such problems.
Visible Pollutants in the Air/on Surfaces
If you can actually see pollutants floating around in the air surrounding you, blowing from your HVAC vents, or simply building up on surfaces in your home, then you should take steps to remove them. As mentioned above, air filtration is an important option to consider. Because these pollutants may be entering your ductwork directly, or building up therein, though, you may also wish to consider professional duct cleaning and/or duct testing services.