Almost half of Australians with diabetes who inject insulin are reusing needles and nearly as many aren't varying injecting sites, a new survey has found.

By the time she had children, Julie Feaunati felt she was well educated about treating her type 1 diabetes.

After all, the Sydneysider had been injecting insulin since she was a teenager and as technology developed, had even learned how to measure her own blood sugar levels and adjust the insulin she was receiving.

So when her two children came along and life became hectic, seeing a doctor about her condition wasn't a priority, and at least eight years passed without a check-up.

"Those years just flew by, when you've got little kids, and you're busy and you're working," the 45-year-old told AAP.

But when Ms Feaunati developed an odd spot of fatty tissue on her regular injecting site on her stomach, she mentioned it to her GP.

She was told her the lump under her skin was due to her repeatedly injecting at the spot, which she hadn't known was such a risk.

A session with a diabetes educator helped her realise how much she'd fallen behind in her knowledge, not just about where to inject but about available needles.

She now varies where she injects and uses needles the right size for her and counts herself lucky things didn't get worse.

"Something really bad could've happened, or I could've suffered long-term complications," she said.

But new research has revealed that Ms Feaunati is far from alone in not always following the best injecting practices.

The survey of 368 Australians with diabetes, supported by medical technology company Becton Dickinson, has found 46 per cent are not changing their injection site every time.

Almost half (49 per cent) are also reusing needles and only 44 per cent are using recommended shorter needles.

The statistics, published on Wednesday come as little surprise to Michelle Robins, a long-term diabetes educator with Victoria's Northern Health.

Teaching good injection technique is core to her work, with issues such as injecting insulin into muscle instead of fat - from using a needle that is too long - that cause unexpected blood sugar spikes or falls.

"That has a huge impact on everything," she told AAP.

Ms Robins said there's a range of reasons people don't do things the best way and it's important for people to be taught not just what to do, but why they should.

But she said it's a good idea for diabetics to at least have an annual check-up with a healthcare professional.

There are about 1.7 million Australians living with a form of diabetes, with almost a third requiring injections.