Generally, it is not necessary to identify the species of mold growing in a residence, and CDC does not recommend routine sampling for molds. Current evidence indicates that allergies are the type of diseases most often associated with molds. No matter what type of mold is present, you should arrange for its removal. How do Molds Affect People? Molds have the potential to cause health problems. Molds produce allergens and in some cases, potentially toxic substances (Mycotoxins). Inhaling or touching mold or mold spores may cause allergic reactions in sensitive individuals. Everyone has different tolerance levels, yet can trigger a wide range of reactions: Allergies, Nasal and sinus congestion, Headaches, Asthma, Respiratory disease Symptoms will typically dissipate after exposure has been eliminated.