I gradually lost my hair when I was around 30yrs, but there is nothing strange about it: my two brothers did the same, like our father and grandfather...
But it is different in women, where hair loss is quite rare but, most of all, easily curable.
Do not worry and please do follow another_someone's advice.
It might be iron deficiency or low thyroid function, for example: both are fixed in a few weeks by magic pills and you'll have your beautiful hair again. Lucky you!