The common site for a nosebleed (epistaxis) to start is from just inside the entrance of the nostril, on the middle harder part of the nostril (the nasal septum). Here the blood vessels are quite fragile and can rupture easily for no apparent reason. This happens most commonly in children. This delicate area is also more likely to bleed with the following:
This is a companion discussion topic for the original article at https://patient.info/ears-nose-throat-mouth/nosebleed-epistaxis-leaflet