Why do i have a soft nodule on the back of my bony elbow. it does not hurt. it is probably 321 cm.how long should it last.when should i see the dr.?

Pls see a physician: May be a lipoma, which is not dangerous but needs to be checked out soon.

Bursitis: This is likely due to fluid in the olecranon bursa. Check out link to see if it looks like this: http://en.Wikipedia.Org/wiki/olecranon_bursitis if it hurts or is red, see a doctor right away. This is often cause by over exertion or trauma. Stop doing whatever activity that can be a possible cause and take a nsaid.