Severe hairfall and baldness. Wrong?

When I shifted to ahmedabad from my native place bihar 5 years back I suddenly started having a lot of hairfall and it was much more than the usual hairfall and within 6 7 month my thickness was reduced to half and I could also see my hair getting lost from upper part of my head also but since I have been really busy with my studies from past years I have completely ignored it thinking it will stop and my hair will grow back but in all these years I have lost a lot of hair and specially from my crown area .My scalp is clearly visible even when I don't oil my hair and it's dry it has became really really thin and since I have bald patches all over my head I need to comb my hair in a way to hide it.my scalp has became itchy too and it's gets oil in a day of shampooing since I sweat a lotand from last 3 month I suddenly see even a lot more hairfall with double the rate of wat used to happen earlier and it's not stopping. do i need to get any blood test done to know wats wrong ? wht is wrg