Woman is fighting for her life after being punched in the face by a Bankstown hospital patient

An elderly woman fights for her life after being punched in the face, choked and thrown against the wall in a hospital emergency department.

The 81-year-old woman is in a critical condition at Sydney's Bankstown Hospital after being confronted by a man at 3am on Thursday.

She was waiting with her two daughters, 63 and 58, both of whom were also attacked by the unknown man.

Doctors said the woman suffered serious facial injuries and has since suffered bleeding on the brain.

The man had previously been cleared to leave after checking in following a car accident and confronted the woman as she went to the toilet.

A man has since been arrested over the attack and was charged in the early hours of Friday morning with causing grievous bodily harm, strangling a person and assault occasioning actual bodily harm. He will appear in court in Parramatta later today.

Police said the woman lost consciousness after her head hit the wall during the incident.

“It is further alleged that the man then strangled the woman and hit her head against the wall, causing her to lose consciousness,” the spokesperson said.

The woman's daughters were also admitted by emergency room staff but have since been released with minimal injuries from the alleged assault.

A spokesperson for Bankstown-Lidcombe Hospital told 9News that no staff were injured and that those who witnessed it were given advice and support.

“The hospital will continue to monitor these staff members to provide ongoing support as needed,” the spokesperson said.

Public access to the emergency department was uninterrupted throughout the episode and the hospital reported this no disruption to patient care or services.

The hospital is helping now police with their investigation.