What are the causes for hair loss? How can I stop hair loss

Hair loss. Can be stress,tight hair clips/bands, hormonal. Check thyroid, androgens, polycystic ovary disease,autoimmune disease,certain medications like b-blockers, amphetamines, low iron( anemia), low zinc levels, fatty acid deficiency , low protein diet ,anoraxia/bulemia, recent childbirth, starting stopping birth control pills, and family pattern of hair. Follow up with a dermatologist.
2 categories. one is natural or hereditary u can't do any thing. other type is known and preventable cause: Hypothyroidism, fungal infections, cancer, chemotherapy.