Half of all Australians are battling at least one chronic disease with heart conditions being one of the most prevalent.
And 20 per cent have at least two chronic conditions, with the figure increasing to 40 per cent for those aged 45 and over.
Health Minister Sussan Ley says the new figures released by the Australian Institute of Health and Welfare (AIHW) on Wednesday highlight the need to reform primary health care.
"As our population ages, we know that the prevention and treatment of chronic disease is an increasing challenge for the health system and Australians generally," she said.
The data covers eight chronic diseases: arthritis, asthma, back problems, cancer, chronic obstructive pulmonary disease, cardiovascular disease, diabetes and mental health conditions.
Ageing is strongly associated with people having two or more diseases, says AIHW spokesperson Louise York.
"Older people are more vulnerable to developing many diseases, and Australians' increasing life expectancy means a greater chance for multiple conditions to arise," she said.
For those aged 45 and over, the most common diseases to occur together are arthritis and cardiovascular disease.
For those under 45, mental health conditions and back problems were the most common combination.
Ms Ley said the newly-formed Primary Health Care Advisory Group was travelling the country over the next three weeks to discuss primary health care reform.
CHRONIC DISEASES IN AUSTRALIA
* Cardiovascular disease affected 22 per cent of adults in 2011-12;
* Cancer survival rates have gradually increased, while the risk of being diagnosed with the disease before their 85th birthday is one in two for males and one in three for females;
* One in 19 had diabetes in 2011-12, including some who are unaware they had the condition;
* One in four reported having arthritis and other musculoskeletal conditions in 2011-12, with the most prevalent including back problems and osteoarthritis;
* Mental health problems are highly prevalent, including in children with 14 per cent of those aged 4-17 in 2013-14 having a disorder in the previous 12 months.
