Must have frequently heard people saying ” I have a bad allergy from mushrooms, I can’t eat it” or ” My nose started to run, looks like all that dust from the carpet triggered my allergy”

What is an Allergy?
Allergies are caused by an overactive Immune system. For some reason, your immune system mistakes harmless substances like dust, food, insect bites, flowers, animal fur for germs and attacks them.
Immediately, our body responds to the call of its immune system. Some of these responses are runny nose, coughing, itchy watery eyes.
Some people develop a skin rash called Hives.
If it is a food allergy, the person may get an upset stomach.

Substances causing allergies are called Allergens.

Interesting Fact:

Allergy and Cold have similar symptoms but while cold can maximum last for 2 weeks, allergies can last for as long as months till the allergen is present around you.