According to doctors at Mayo Clinic, mold allergy symptoms are triggered by an overly sensitive immune system response. When you inhale tiny, airborne mold spores, your body recognizes them as foreign invaders and develops allergy-causing antibodies to fight them.

After the exposure has passed, you still produce antibodies that “remember” this invader so that any later contact with the mold causes your immune system to react. This reaction triggers the release of substances such as histamine, which cause itchy, watery eyes, runny nose, sneezing and other mold allergy symptoms.

However, only certain types of mold causes allergy to the body. Some of the most common molds that cause allergies include alternaria, aspergillus, cladosporium and penicillium.