Hello dear! I understand your concerns you have described in your query. Slightly yellow discharge from nostril, may be caused by a viral condition that has affected your nose mucosa or a bacterial infection too. Dusts and foreign bodies may cause secretions from the nose too. If it does not happen to often, don t worry. Just wash your nose cavity throwing drops of normal saline solutions, in both nostrils. That will help clear your nose mucosa and clean off the secretions. If you have other symptoms and they last a lot, a rhinoscopy would be necessary to see your inner nose, and this can be done by any doctor at your healthcare doctor, or an ENT specialist. If you find helpful this answer please kindly click I find helpful this answer and write a review to help us assist you better. I hope you will be fine. Wishing you a good health! DR ERIOL.