A stroke patient in the bush may notice their symptoms in the early morning, arrive at a hospital for a scan three hours later, before being flown to a specialist unit in a major city by noon.

That time frame of five hours and 10 minutes was the experience of one country stroke victim, who needed to be flown to a major hospital by the Royal Flying Doctor Service.

"The time for stroke treatment outcomes to be the best is one hour," the service's stroke project manager Zoe Schofield told the National Rural Health conference in Brisbane on Wednesday.

Diseases of the circulatory system were the most common reason for rural patients to be flown for medical treatment between July 2019 and April this year, when there were about 120 retrievals per week.

That's more retrievals than for injuries and poisoning, abnormal test results, respiratory and digestive issues, infections, and pregnancy and birth.

Ms Schofield said stroke is a leading cause of death, causing 20 per cent of deaths in people with cardiovascular disease.

"What's even more important is the high rates of disability that could be reduced due to early intervention," she said.

"Our saying is 'time is brain', which means if we can act soon, we can improve outcomes."

The service is on track to have small helmet-style brain scanners on their aircraft by 2023 in the hopes of diagnosing strokes earlier, in partnership with the Australian Stroke Alliance.

The technology needs to be paired with education about the onset of strokes, she said.

"We need to improve technology to get people diagnosed.

"But the only way we can really improve patient outcomes is to work together across all health services, identify strokes early in community so that we can get people to the right facility."

The service's research from 2020 shows that within an hour's drive in rural and remote areas, 42,805 people do not have access to local primary healthcare, and 65,050 people had no access to a GP.

Nearly half a million people have no access to a nurse-led clinic, and more than 100,000 people have no access to dental and mental health services an hour away.

Director of programs and policy Lauren Gale said the service will release new figures this year to identify health service gaps across Australia.

"While we might be very well known for emergency aeromedical retrieval services, we know the only way to improve health outcomes and avoid the need for such urgent action is to improve primary health care."