For about 6-8 weeks whenever i've had a particularly bad dry cough. it is worst whenever i get up and walk. what's going on? don't smoke

Bronchospasm: You may have a bronchospastic disorder. Meaning, Your airways may be sensitive to an allergic, chemical or environmental irritant which causes them to spasm & even produce more mucus. See your clinician if it continues or worsens.

Asthma possible: Recurrent and chronic coughing can be a result of untreated or undiagnosed asthma, or other problems including infection, acid reflux, allergies or structural problems of the heart or lungs. A complete history and physical by your physician should be performed.