Plagued at home by sneezing, an incessant runny nose, and watery eyes? You may be 1 of 40 million people who suffer from indoor allergies, according to the American Academy of Allergy, Asthma, and Immunology. Luckily, there are ways to get relief. With a bit of planning and a little extra work, your house can be a haven for those in your family with indoor allergies. Follow these steps to start breathing easier. Clean Up Dark, Damp Spaces In basements, bathrooms, or other places where moisture collects, mold can form and release spores that cause allergies to flare up. You may smell the telltale musty odor before noticing visible mold on windows, tubs, or in basements. To fix, dry up the moisture and seal any cracks, leaks, or drips. Keep the humidity in your home below 50 percent. A dehumidifier (and monitor) can help keep moisture in check. To clean …