almost all hair problems come from bad health .. btw. the olive oil thing is a conditoner not for hari fall out or dandruff.
first i'll adress dandruff ..
dandruff can be caused by differnt things ..1 over active sebacious glands that means oily hair
2 build up of products in you hair just to name a few..
hair fall out most likely is your natual hair fall out. eveyone looses around 40 hairs a day. which compared to whats actually still attached to your head is not very much . i wouldnt worry about it, unless its coming out in hands full .
heres a more comprehensive list of causes of dandruff