My nose runs uncontrollably when i bend over sometimes just drips out what could cause this should i be worried?

Sinus: The sudden discharge is likely from the mucus collected in your sinus draining when the head position is at a certain angle- we see this often in people doing sinus irrigation which left some saline in the sinus cavities. By itself, this is just inconvenient. If the discharge is unilateral and a history of head trauma, will need to check for fracture which can be serious.