let me answer your doubts.
1. firstly : there is no need to worry , you have had a problem for 10 years but have nt taken a professional opinion. i believe the time has come .
there are quite a bit of causes of nasal bleeding
, the nasal area is quite a vascular area and hence even small trauma can cause significant bleeding .
it can be something very trival like nose picking to a even malignancy .
what you need to do :
see a ENT specialist
at the earliest , get an examination done , if required a nasal endoscopy
, CT scans of the nose and para nasal sinus
. this would help in coming to a conclusion . a biopsy
would be only required at a later stage . please do post in your endoscopy as well as CT scan reports .
i hope this helps