What Causes Nose Bleeding?

I am 23. I usually get nosebleed often ever since I was a kid. Usually it happens every month for mostly 4 to 7 days at most. This past 2 months I have been getting nosebleed everyday. Sometimes it happens at least 2 to 8 times a day. Sometimes it just happens without me touching my nose or blowing my nose. Is this serious problem now?Should I go see a doctor?

THanks