Normally 50 to 100 hair fall happens everyday. But if its more than that we call it as telogen effluvium. The reasons could be past 6 months if you have suffered from major illness like dengue, tyhoid, etc, major surgeries, stress, hormonal imbalance,  nutritional deficiencies like iron deficiency or vit b 12 deficiency etc. So check the Hb, thyroid. In females we have to rule out PCOS, so get ultrasound done. Peptide serums(foliserum at night for 4 months) available,oral biotin supplements (tan xtraglo/ keraboost for 6 months)help in hair loss. Myth about hair loss is shampooing doesn't cause hair fall or hair growth or greying of hair. It just cleans your scalp.