Jocelyn Askew's son, Patrick, fell off his skateboard at high speed, hitting his arm and head on February 19. He was treated for a broken wrist and sent home without being checked for head injuries, Ms Askew said.

It is one of two cases the hospital has confirmed it has recently reviewed in which a brain bleed or aneurysm was possibly missed.

Ms Askew said following the incident she contacted minister for health Meegan Fitzharris' office seven times over the space of a month to get answers.

"I reached out to them seven times and in those seven times I think on the sixth call somebody said that the request was put through to ACT Health," she said.

Following the story published in The Canberra Times on Monday, Ms Askew said she received a phone call from the minister's office.

"I said, you've got to be joking - you're ringing me now? How coincidental that you're ringing me once the story has been printed," she said.

"The woman on the phone said they've referred it on to ACT Health for investigation or something like that and asked me if there was anything else they could do and I said nope - you haven't done anything, why start now? I've had to do it all myself."

A spokeswoman for Ms Fitzharris' office said they raised Ms Askew's concerns immediately with ACT Health, which she said was appropriate and ensured the department and the hospital made contact with Ms Askew "so she was aware of how her enquiry was being followed up".

"We welcome the news that Calvary has launched an investigation into this case, and would urge anyone with concerns about their treatment to also consider contacting Health Care Consumers or the Health Services Commissioner."

Immediately after the incident, Mr Askew's friends took him to Calvary's emergency department where he waited to be treated for more than 12 hours. He was eventually treated for a broken wrist and sent home.

The next day Mr Askew had an appointment at Canberra Hospital for a follow-up. That was when a nurse noticed his behaviour and sent him to the emergency department. Within hours he was in emergency brain surgery as doctors worked to contain a brain bleed growing bigger by the hour.

Ms Askew believed Patrick showed signs of head trauma at the hospital; complaining of headaches, face pain, vomiting, a severe headache, confusion and not being able to remember the accident.

She said little attention was paid to his head injury or exploring the possibility of a concussion and the likely reason was because he was dismissed as being drunk.

"I trusted the doctors and all the medical staff there and nobody said that you need to be looking out for signs, nobody gave me any information regards to head injuries," Ms Askew said.

"I actually got better medical treatment for my son when we lived in Jakarta, Indonesia than I did at Calvary Hospital."

Ms Askew said she would be making an official complaint to the Human Rights Commission and to the Australian Health Practitioner Regulation Agency.

"I've got absolutely no faith or trust in the ACT health system. I just think it's ridiculous and it makes me reconsider things like now for instance, if something bad was to happen, where would we go?

"We're just hoping that this story is going to make people be a little bit more aware and perhaps ask more questions."