 [ Symptoms ] i have been diagnosed to indoor allergens yet i am not allergic to anything how is this possible did i misdianose myself  i have been having a small headache and my nose has been runny and acting up i have been sneezing a lot getting a fever as well as experiencing nasal congestion i thought it be a cold because my sister had one earlier and it is been spreading recently but when i was diagnosing myself through this website the top answer was indoor allergens but i have never been allergic to anything and i barely believe i will just suddenly develop an allergy at the age of 16 [ Disease ] im 46 years old and have suffered with indoor allergies all my life it can be somebody having a cat or dog and visiting you or even your furnace or air conditioner running its worse certain times of the year for me