Teleport desintegrate you

After a short channel you lose 100% of your own current health. The only small consolation it to not give your enemy laner the bonus gold for your death.  

It seems like several people run teleport, mostly in top lane to do like the pro players in lcs and they really don't seem to grasp that part of the spell. They use teleport at so wrong moments that I instantly react by using MY teleport in their lane to correct their lack of presence. Or immediately leave what I was doing to roam in their lane.

Please, if you go top and you don't master the macro positioning over the map do not bring teleport ! Everytime you use is, you kill yourself instantly. It's kind of a big price for the spell. It can go much more wrong then a heal spell or ignite.