I know this is an old thread but its recently been posted in ... so I thought I'd chime in just incase it hasn't been mentioned (I didn't see it.)
Make sure to get your blood sugars and glucose, hormones and cholesterols check. Get a FULL work up of blood work done.
Some times its even good to go and see an Endocrinologist about this problem and get the proper work ups done. I know it sounds weird to get that stuff checked for your hair but hormones and glucose can not only cause excess hair growth but can also cause excess hair loss.
I've been reading a lot about hormone stuff lately and this is mentioned a lot more than you'd think. It's weird to me too, that doctors wouldn't test these things when a body starts doing odd things. These problems with glucose/insulin/sugars and all that also are hereditary ... not only 'hair loss'. There may be an actual reason other than genes.
HTH