Here’s a fact: nearly 50% of houses in the US have mold. Here’s another fact: 40% of people who live in moldy homes can develop asthma or other respiratory problems as a result. But with mold exposure symptoms being so similar to that of a cold or a seasonal bout of allergies, it can be hard to identify them as such. Add to that the fact that many different kinds of mold that can exist throughout your home, and you may start to understand why mold is a silent health hazard.