Hi Neethu ,thanks to have trust on Health care magic ,There are many causes of hair fall
those are as follows :-
1. Excessive and crash dieting
go for T3 T4 THS test that can reveal it .
3. Typhoid or occult typhoid go for widal test
to know this
4. Anemia is one of most common cause of hair fall
5. Kidney ailments
6. Just after long illness
7. After pregnancy
these are some common causes ,more over Dandruff
,androgenic diffuse loss
Vit,A excess ,Fungal infections ,are some local causes .
You should go to your dermatologist
in this regard he will defiantly find the cause after investigations . Biotin is a hair vitamin ,good for hairs ,diet with protein is must for good hairs as hairs are made up of Protein called keratin . take care bye Dr Prakash Roy