I have this problem...on and off i have white mucous discharge from the nose and i have a bad habit of regularly spitting trying to get rid off it...it could be a virus or infection...but why does it come every 3 weeks? Immune system low? Smart replies please
SO, NOW FOR THE INTELLIGENT ANSWER.... Mucus over-production is caused by an irritation such as allergy, virus, or bacteria. It's your body's attempt to flush out the offender. In your case, the mucus is clear, seems to come and go, and doesn't come with other symptoms suggestive of infection (fever, malaise, pain, etc).
Most likely, you have simple allergies to airborne allergens. You can try taking a newer generation antihistamine such as Allegra or Zyrtec every day for 3 weeks straight and see if it improves. If it does, you have a good idea of what's going on. Then, you have to figure out what you are allergic to in your environment. If you can't find something obvious such as a cat, dust, a tree near your window etc, then you should get allergy tested (it could be airborne molds/pollens or 100 other things) and have an immunologist take a look in your nose. Sometimes just the color of the turbinates in the nostrils inside tells a lot...raging red=infection, purple/blue=allergy. Then, he can prescribe one of the newer nasal sprays such as astelyn sodium or Flonase, etc. Good luck.