Australians are reminded the Las Vegas shootings could trigger feelings of grief, particularly for those who've previously experienced a sudden loss.

Reacting to the Las Vegas shootings by posting on social media can be a manifestation of grief and is perfectly normal, an expert says.

Grief isn't just someone who is tearful. Grief can be expressed in a range of emotions and responses, says Mr Christopher Hall, CEO of the Australian Centre for Grief and Bereavement.

"People get angry. Or anxious. Or scared. They also do things like write books, petition governments, create art, and post on social media," Mr Hall said.

As the names and faces of the 59 victims emerge, Mr Hall - an experienced grief counsellor - says it's important to be mindful of the often unexpected and intense emotions they may trigger.

"I think sometimes people are surprised by the intensity of their reactions," Mr Hall said.

He says sharing your reactions online to an extent can be beneficial and healthy because it helps people normalise their emotions.

"Largely in our culture grief is a private experience, it's not shared or discussed; we have a view that in a couple of days people will return to normality and I think what an online presence enables people to do is to receive some kind of validation for their experience," he said.

"I think we are often suspicious of people that have intense reactions to these sorts of events but we need to understand that these events often pull at the threads of other people's experiences of loss, and so in a sense has the power to reactivate previous losses, particularly for people who've had an experience of death which has been sudden or unexpected or traumatic," he said.

It's also completely normal for people who are not directly involved in situations like these to experience grief, Mr Hall added.

"In situations like this, the public and private become intermingled. We see this sort of thing with the death of public figures, and it's certainly present in situations like mass shootings" he said.

"It's the nature of the fact that when we live in such a hyper-connected universe we're able to learn about people, we're now seeing photographs of people who died, it's becoming personalised in a sense rather than just a large-scale unidentified tragedy," Mr Hall said.

People are also grieving their loss of perceived safety in the world, Mr Hall noted.

"Sudden and unexpected deaths like this challenge our beliefs about our own safety and produce widespread feelings of anxiety. As grief and bereavement practitioners, we know that those who struggle the most are those who can't make sense of the loss. And there are a lot of people right now who are struggling to make sense of these events" he said.

Anyone who is deeply trouble is urged to reach out and seek support.