Is it possible that my office is making me sick?

I have allergies, and suffer from allergy-induced asthma. Lately, I only really seem to have symptoms in my office. I get dizzy and congested, and my chest feels like it's made out of lead. I use allergy medications and inhalers more at work than at home. Once I'm in my car and on my way home, my symptoms lessen to the point that they practically dissapear. Could it be the office making me sick?