Reasons of Bleeding Nose

I was returning from a tea break in lift and stopped by reception to collect a courier when from nowhere I felt some flow from nose and I was not bad at guessing it was blood. I was surprised as I never touched my nose for any nail contact with the nose . So I was looking around for reasons for a bleeding nose on net and to my surprise I found many more causes other than finger nail trauma.

I would like to mention some points which briefly describes the reasons for a bleeding nose.

Most common reasons of a bleeding nose are

1) Excessive nose picking
2) Trauma to nose
3) Some nasal fracture
4) Viral Rhinitis
5) Acute Sinusitis
6) Foreign things in nose
7) Deviation of the nasal septum
8) Atmospheric changes
9) Some kind of growth in nasal cavity such as tumor.
10) Hypertension can be the reason of a bleeding nose in old age.
11) Heart diseases
12) Pregnancy
13) Some drugs like pain killers.
14) Acute infections including typhoid, pneumonia, malaria, dengue fever, measles etc.
15) Idiopathic - at times the reason of nose bleeding may not be clear.