Hello there Welcome to HealthcareMagic. Hair fall is a universal worry. Its causes, if they are something recent, could be due to some acute illness like febrile illness, severe infection, major surgery, and severe trauma.Some hormonal imbalance( hypothyroidism)Even chronic illness like systemic diseases(SLE),liver disease.But the more common causes, which could be one in your case, might be like crash dieting, anorexia, low protein intake, and chronic iron deficiency.So please correlate them.Better consult a dermatologist and get it treated. Above all you need to have a nutrient diet enriched with Vitamins(A,C, E).Take care.