Is it possible to over-use salt water nasal douche? been using it for 2 years 2x per day to clear irritants + allergy meds. worried about any damage.

Study points to yes: Saline irrigation can be beneficial when used for a short period of time. A study presented at the 2009 College of Allergy, Asthma, and Immunology suggested that chronic use of saline was counter productive. Although it removes pathogens when used from time to time, chronic use may remove the "good bacteria". Usually 1-3 weeks of use once a day is enough. If symptoms persist, see an ENT.