Mold grows where it's damp, so you're likely to find it in rooms with a lot of moisture or humidity (bathrooms and utility rooms) or without windows (basements). It can also show up in kitchens underneath trashcan lids or where condensation may have built up. To prevent mold from taking up residence in your home, clean your bathrooms -- and any other mold-prone area -- thoroughly and often with a bleach-based solution, paying particular attention to walls, windows, fixtures and shower curtains. If you have a carpeted bathroom or basement, make updating the flooring a top priority. Air movement and climate control also help, so consider installing fans, keeping your unit clean, efficient and set at 70 degrees Fahrenheit (21 degrees Celsius), and using dehumidifiers. Aim to keep the humidity in your home below 50 percent. One last thing: Keep in mind that houseplants can collect mold, so you'll want to remove any in your home if you have a family member sensitive to it.
But mold is just one allergen you'll have to combat. There's also pet dander and dust.