Causes of hair thinning in young men ???

Thinning of the hair is a natural part of the aging process,  but many men experience hair loss prematurely. About 50 percent of men suffer from a type of hair loss called androgenetic alopecia, or male pattern baldness. 

DHT

DHT, or dihydrotestosterone, is an adrogen, which is a product of the male hormone testosterone and the root cause of 95 percent of hair loss in male pattern baldness. Men have more DHT present in the body than women, explaining why they suffer more from hair loss. DHT kills the hair follicles by blocking them from receiving the nutrients they need to survive.

Alopecia Areata

Alopecia areata is the name given to hair loss when it appears in patches, and it can be another possible cause of hair loss in young, healthy males. An autoimmune disease, alopecia areata is the result of an overactive immune system attacking its own cells.

Other Forms

hair loss can be caused by poor nutrition, medications, hormonal changes, overly tight hairstyles, scarring and inflammation. Hair loss can also be caused by emotional or physical shock; this is known as telogen effluvium hair loss. In most cases these forms are often temporary.