A systemic review was performed evaluating 31 studies that examined the association between indoor dampness, mold and the outcomes of nasal allergies and conjunctivitis. The most strongly related factor was mold odor. Significant association was also found for visible mold. The strong link to mold odor suggests that microbial causes are important. Indoor allergens and odors are important contributors to respiratory illness. The importance of odors as triggers for rhinitis and asthma is well known. Avoidance parameters should be given to patients to include: keeping humidity low, 35% if possible and allowing adequate ventilation. Indoor plants should be limited and live Christmas trees should be avoided. Avoiding foam rubber pillows and mattress as they can become moldy. Lastly, HEPA air cleaners can remove mold spores from the air.