Woman found injured on Sydney footpath

Police are trying to figure out what happened to a woman found with head injuries on a footpath in Sydney's northwest.

A woman has been found with serious head injuries on a footpath in Sydney's northwest.

The woman, believed to be aged about 60, was found in Marsden Road, West Ryde, on Sunday evening and taken to hospital, where she remains in a serious condition.

Police are still trying to work out what happened.