Sydney man's finger hacked with machete

A man's finger has been hacked off with a machete by someone he knew inside his western Sydney unit.

Police say the 43-year-old also suffered a severe injury to his left arm and extensive cuts to other parts of his body during the attack in Carramar early on Wednesday.

He was taken to Liverpool Hospital in a serious but stable condition.

Police believe the men are known to each other and are treating it as a targeted attack.

The offender has not been caught.