Suggest Remedy For Hair Fall

my hairs have been falling out from past 6 months.....n i am only 14 yrs old...few hairs are thinning from bottom.....n now my ponytail is vvv small....it used to be a pretty thick one before....my ultrasound..thyroid n haemoglobin reports are also perfectly normal..wats the problem...y are my hairs falling out...any possible solution