Man hit by train in Sydney's west

A man has suffered critical injuries after apparently taking a shortcut across train tracks in Sydney's west and being hit.

A man is in critical condition after being hit by a train in Sydney's west. (AAP)

A man is in critical condition after being hit by a train in Sydney's west.

The 33-year-old is believed to have been taking a shortcut across the tracks about 400m from Doonside Railway Station when he was hit by an express passenger train shortly before 9pm on Friday.

A friend who was with him called emergency services, and the man was taken to Westmead Hospital with head, chest, abdomen, thigh and pelvic injuries, police said.

He remains in hospital in a critical condition.