The Newcastle woman is taking part in 5k a Day in May, which raises funds for asthma research as well as spreading awareness of the need for people to have and follow asthma management plans.

The initiative was started by Newcastle business owners Kerri-Ann Hooper and Natalie Doolan.

Ms Miller has been sharing her heart-breaking story this month “in the hope that it will save someone else’s life”. 

“One Saturday after playing soccer and spending time with his girlfriend they headed off to a party with friends,” Ms Miller said.

“In the early evening he asked me to come and collect him because his asthma was playing up and his medication wasn’t working.

“We got to the hospital around 9.30pm and at 11pm Ryan had a serious asthma attack leading to a respiratory arrest.”

She was told by hospital staff they held “grave concerns” for her 19-year-old son and to “call the family in so they can say their goodbyes”.

Her son died a few weeks later as a result of the hypoxic brain injury he sustained at the time of the respiratory arrest.

Ms Miller said Ryan had an asthma management plan in place and carried it in his wallet but he had not been following it.

“Like many other people Ryan did not take his asthma seriously enough,” she said.

“Just because everyone knows someone with asthma doesn’t mean it’s not a dangerous condition.

 “If you or someone you love has asthma I want you or them to have their asthma management plan reviewed, carry it and most importantly, follow it.”

According to national statistics, there are around 400 deaths in Australia every year from asthma. 

One in nine Australians, around 2.5 million, have asthma yet only 20 per cent of people aged 15 and over and four per cent of children (under 15) have a written asthma action plan.

During May participants can walk, run, ride or swim 5km every day to raise money for Asthma Foundation QLD and NSW.