Repetitive stretching of the nostrils can enlarge the nostrils. Nostrils need to be large enough so the fingers will fit. That being said, if one nostril is much larger than the other, you may have the nostrils attached in a different place on both sides or the midline of the nose may be shifted. You can have the nostril size reduced by alar base reduction that should give more symmetry. A photo would help.
Nasal asymmetry and rhinoplasty
In my expert opinion, I do not believe that picking your nose would cause one nostril to become larger than the other. In any event, nostril asymmetry is a relatively common problem in patients seeking consultation for rhinoplasty. Depending on the severity and anatomical reason for this asymmetry surgery may be an option to correct this. Without pictures it is impossible to give you any further information. I would recommend you consult with a board – certified plastic surgeon or facial plastic surgeon to discuss this further.
Yes, picking your nose can increase the size of the nostrils if there is excessive stretching and pulling. If one nostril is larger than the other, as you mentioned, this could be solved relatively easily. However, no definite answers can be given without seeing you in person. I recommend you see a doctor is this continues to bother you.
Hope this helps!
Dr. Ali Sajjadian