Being iron deficient might make you feel tired. Or it could make you dizzy. Or a bit short of breath. Or your libido could drop off a cliff. You may even have a desire to eat ice.

The symptoms are so varied and some seemingly innocuous that the condition - which affects one in three people worldwide - is going undetected and undiagnosed for a growing number of Australians.

A recent survey of 1033 Australian adults, funded by global biotech company CSL, found one in four had never heard of iron deficiency or what impact it could have.

But left untreated it can have very serious implications, leading to iron deficiency anaemia, where the body can no longer make the necessary number of healthy red blood cells.

Roberta Sowden, 53, from Sydney's northern beaches had no idea she had iron deficiency until a regulation test as a blood donor showed extremely low levels in 2017.

"Once I received the results it made sense," Ms Sowden told AAP.

"I was playing soccer at the time and after an hour and a half of playing I was absolutely shattered - which seemed really weird to me how exhausted I was considering I wasn't on the pitch for the whole time."

Looking back, she had probably been experiencing exhaustion and difficulty sleeping for some years before her diagnosis, she says.

"I had put it down to being a parent, working full time, having a busy life, not sleeping so well - I thought that was just life," she says.

"I certainly notice that I feel I have more energy now on a more regular basis.

"At the time it was ongoing fatigue and it felt like you were really recovering. It dragged on and dragged on and dragged on."

Ms Sowden's doctors determined her lifestyle and diet were not contributing vastly to her diagnosis. It was, in fact, her regular blood donations.

"I just donate the plasma now. Not donating the whole blood has been my most significant change," she says, adding she feels lucky to have detected the issue thanks to the donation process.

"I may not have looked into it at all (otherwise). It was fortunate," she says.

Haematologist and iron deficiency expert Dr Lisa Clarke says more Australians should be listening to their bodies and taking iron deficiency seriously.

"Iron deficiency remains overlooked by patients and healthcare professionals as we don't have a good understanding of the symptoms. Often iron deficiency is only addressed when anaemia has developed," says Dr Clarke.

"By recognising the signs early and speaking to your GP, we can take an important step towards early diagnosis and treatment."

Those most at risk of iron deficiency include women, children, adolescents and people living with chronic diseases.

"It's particularly important for women to be aware as they are at higher risk throughout their life due to menstrual loss and pregnancy," says Dr Clarke.

"This means that menstruating women need over twice as much iron from their diet as men so if they're not getting enough they will become iron deficient."