This is the number one question we are asked by our customer's, and in most cases of your nose can be a great starting indicator. This of course along with sinus, allergy, and other negative related health symptoms you may experience! It may not be the scientific answer you were expecting, but if you home has a strong musty odor there is a good chance your home has mold. At the very least, those musty odors are gasses emitted by some sort of MVOC’s (Microbial Volatile Organic Compounds) which in fact may be even more harmful to your health than “mold”. This is why mold isn’t the only thing you need to worry about when it comes to the safety & health of your home. Yes, it is very important to reduce mold levels in your home, but in reality your goal should be to reduce all potentially harmful microorganisms to safe levels! There are a number of different microorganisms potentially creating health risks in your home including bacteria, dust mites, animal dander, viruses, etc. Mold in high levels is just one of those microorganisms liked to very serious health risks. Also, It is a good thing to note that of great of an “indicator” your nose can be, it in no way leads you directly to the source(s). This is why it's highly recommended that you hire a professional to inspect, potentially test, and remediate all harmful microorganisms from your environment! We notice almost always when customers try to remediate mold on their own they end up making the situation drastically worse and costing themselves thousands more in the long run. Remediating harmful toxins & mold from your home is an intricate process that takes mold professionals years of education and field work to fully comprehend. This is why painting over mold, using unsafe chemicals, improperly handling infected materials, and so on will just cause the toxins to spread even throughout in the air further into your home. Please don’t risk your health, time, and money trying to remediate mold yourself! Hire a knowledgeable professional and save yourself the stress!