Sneezing, running nose, also a sore throat after waking up in the morning, and last but not least frequent headaches. Black mold can sometimes be dangerous, but most of the time it is just an allergy nightmare. If you have high volumes of the mold you may want to consider remediation. But if the levels are low, hit it with some very diluted bleach, and be careful not to breath the bleach or mold in while cleaning.