Well to be more precise, my right nostril is running! I can feel it leaking about half way up the nostril, then I sneeze violently several times. What could be causing this - I don't have a cold.
Just a little more information please.
I presume that the "running" side of your nose is not also blocked.
I presume that you are not taking betablockers e.g Bisoprolol or other blood pressure tablets e.g Enalopril,
Not taking anything, and no other symptoms of a cold or blocked nose. It doesn't happen all the time, a couple of times a day at long intervals. For example this morning it hasn't happened at all since I woke up. Maybe its cured!
OK...certainly sounds like an allergy.
On a personal note, i would prefer an anti-histamine nasal spray rather than antihistamines by mouth............