Mold is a type of fungus that can grow both indoors and outdoors. Mold can enter your home through open doors, windows, vents, and heating and air conditioning systems. Mold can also be carried into your home on your clothing, pets, or shoes.
Mold can cause a number of health problems, including:
Allergies
Asthma
Coughing
Sneezing
Itchy, watery eyes
Runny nose
Skin rashes
Headaches
Fatigue
Nausea
If you have mold in your home, you should remove it as soon as possible. Mold can be removed from hard surfaces with soap and water, or with a solution of bleach and water. Mold can also be removed from porous surfaces, such as clothing and carpeting, by laundering or dry-cleaning them.
If you have a mold problem that is too large to handle on your own, you should contact a professional mold removal company.
https://www.cdc.gov/mold/faq.htm
https://www.mayoclinic.org/diseases-conditions/mold-allergy/symptoms-causes/syc-20351713
https://www.webmd.com/allergies/mold-allergy#1