Is it possible to lose so much hair?

[LoosingHair]

My hair never stops shedding and I'm not even on any medications. Have been losing around 500 hairs a day for a year now and my hair loss has become very obvious. The right half of my hair line to a third of the way back the top of my head is almost non existent. However the left side of my hair line has no recession but you can see straight through it when my hair is up. The rest of my hair is also very thin. Could this be Male Pattern Baldness or maybe something else?

 

[LoosingHair]

I forgot to mention that the hairs that i shed do not grow back. Would propecia stop my hair falling out?