Her son Ryan died from an asthma attack at age 19.

Ryan was one of almost 170 people to have died from asthma in the Hunter New England region over the past decade, NSW Health data shows.

Ms Miller, of Mayfield, thinks about Ryan every day. Presently, those memories are particularly vivid.

Today is the 10-year anniversary of Ryan’s death.

About one in eight people suffer from asthma in the Hunter New England Health District. It’s a similar picture Australia-wide.

Ms Miller said everyone knows someone with asthma.

“It is kind of normalised,” she said.

“I believe as a community we are far too complacent about asthma. I think this occurs because it’s so prevalent.

“You often hear people say ‘oh it's only asthma’, but that's a seriously dangerous point of view.”

Ms Miller rails against people who suggest that asthma can be managed with breathing exercises.

She said an unqualified person recently advised a friend that her grandchild probably didn't need medication and “they could just get him blowing up balloons”.

Then there was the insensitive troll on social media who said breathing techniques could have saved her son.

“While some people might believe breathing techniques can ease symptoms, which of course is possible, it’s dangerous to give advice when you're not a qualified medical practitioner,” she said.

University of Newcastle Professor Vanessa McDonald said “many asthma deaths are preventable”.

“It is recommended that individuals have and follow an updated asthma action plan,” said Professor McDonald, a Hunter Medical Research Institute asthma researcher.

Professor McDonald said asthmatics should “avoid their asthma triggers, take their asthma medications as directed and have a regular check up with their GP”.

“If people are experiencing a worsening of their asthma symptoms, they should never delay seeking medical assistance.”

Dr Ian Charlton said many sufferers “don’t quite understand” the role of preventer puffers in asthma.

“We now can just about control asthma completely,” Dr Charlton said.

“But you need to control the underlying inflammatory process – the allergic process.”

Dr Charlton said sufferers will often use their puffers for a couple of weeks or perhaps a month after an attack, then think: “I’m pretty good, I’ll stop my puffer”.

He said it might only take 10 doses of dust, pollen or some other trigger to cause another asthma attack.

“Patients end up on a roller coaster ride, going from one attack to the other,” said Dr Charlton, a member of the National Asthma Council General Practitioner Advisory Group.

But if asthmatics use their preventer medication, “they can lead a completely normal life”.

“They can keep their airways functioning at the 100 per cent mark,” he said.

“But many of our asthma patients function at 70 to 80 per cent, which is when their symptoms start to happen.

“It doesn’t take much to tip the balance and send them crashing down and into hospital.”

Since Ryan’s death, Ms Miller has been an advocate for asthma awareness.

Her role makes Ryan's death feel a little less futile.

Her message is: “Be diligent, have regular check-ups, have an asthma management plan in place and follow it”.

“If your GP is complacent, find a new one,” she said.

Sometimes doctors don’t make clear the risk of death from asthma.

“No doctor ever actually verbalised to me the risk of death from asthma.

“It was naive of me, I know. If you can't breathe, you die.”

She said Ryan did have an asthma management plan, but he was not following it.

He had run out of his preventer medication three weeks before he went into respiratory arrest.

Ryan’s story and his mum’s advocacy have influenced many people.

“I have lost count of the amount of texts, calls and social media messages I have received,” she said.

A recent message on social media said: “I just wanted to say I was diagnosed with asthma as an adult. And I hate to admit that I am terrible at times at managing it.

“So thank you for all your amazing reminders to not only have a management plan, but to actually use it. You are my asthma angel without even knowing.”

While her advocacy work helps her cope with losing Ryan, it’s hard when she sees his friends reach milestones like 21st birthdays, weddings, having children and travel experiences.

“I am delighted for them and at the same time sad that we won't get to enjoy them with Ryan. Equally he is not here to share our special events either.”

Next year, Ryan would have turned 30.

When Ryan was a little boy, he and his mum would often get stopped by people admiring his “big brown eyes and long eyelashes”.

“One of his best mates had a little boy. Ryan is his middle name. That was very touching,” she said. 

“Every time I see that cute little boy’s face on social media I smile because he is gorgeous and happy, just like Ryan was.”