hair thinning

the front side of my hair is thin back not the back it is thick it been like that for a while now. The front side of my hair never grows is always thin. I tried growing out but it never Grows. When i shaved my hair bold the front side of my hair grow a little bit but it is still  thin and comes to  the some length as before you can see the scalp to. What is going on. The front side of my hair is thin never grows, never shreds or falls of. Why is the front side of my hair like that, does anybody have answer because i find it strange.