Hi ! Thanks for your query. Dandruff is a chronic condition that comes and goes. It is due, in part, to a yeast that lives in the scalp. There are many effective treatments including shampoos made of : ketoconazole, selenium sulfide,  zinc pyrithione, You can use a ketoconazole containing antidandruff shampoo like “Scalpe”after washing scalp with your regular shampoo thrice a week for a month and then as maintenance at least once a week for 2 months.You need to leave the product on for 5 to 10 minutes prior to rinsing.  This will help to control the yeast responsible for dandruff. Avoid hair styling products and gels on scalp. Do not keep scalp oiled for long time. Do not share combs etc. Air dry your hair. Avoid using hair dryers. Do not scratch or itch. Following healthfeed should be helpful"Understanding Dandruff" by Dr. Jolly Shah Kapadia - https://www.practo.com/healthfeed/understanding-dandruff-8830/post

Fungal infections (such as tinea capitis),Folliculitis,Hypervitaminosis A,Iron deficiency or malnutrition in general can cause hair fall..  Seborrheic dermatitis, a condition in which an excessive amount of sebum is produced and builds up on the scalp (looking like an adult cradle cap) is also a symptom of hormonal imbalances, as is an excessively oily or dry scalp. Both can cause hair thinning. Consult dermatologist