Hi doctor, i'm 19 and i have a little bald in front of my head. it happen since last year, when i 18. how could i get my hair back?

It is unusual: for a teen to lose his hair. You should see a dermatologist to be certain that you don't have another reason for hair loss such as a fungal infection or non-androgenic alopecia. If you DO have early male baldness, then starting medications (such as minoxidil and dutasteride) early will help slow or stop your hair loss. Consider a HealthTap Concierge visit for more personal advice.