Lack of humidity is a culprit in may indoor plant deaths, especially during the winter. The change in humidity from summer to winter is great enough, but if your houseplants vacationed outdoors for the summer, the transition is even greater. If you did move your houseplants outside for the summer, be sure to bring them back in before the heat is turned on. Preferably bring them in while the windows are open, so the transition is eased a bit.
You may first notice a low humidity problem as browning leaf tips on your houseplants. As a plant dehydrates, it can start to look withered, puckered or simply drop its leaves.
To insure your houseplants get the humidity they need, first research how much your particular plants actually like. If your house tends to be dry, you can increase humidity around your houseplants by placing a tray of pebbles under the pots, filling the tray to just below the pots bottom. Do not let your plants sit directly in the water or you will be creating a whole other problem. You can also provide some humidity by misting your indoor plants daily. If you have a great many houseplants, you may want to invest in a humidifier. Its good for your skin and even your wood furniture too.