More than 40 per cent of New Zealand women have problems with incontinence, according to new research.

Otago University Professor Jean Hay-Smith, co-author of the research which was published in The New Zealand Medical Journal on Friday, says the social stigma of incontinence means many women are not getting the help they need.

"There is no question that incontinence is considered embarrassing at the very least, often shameful depending on the culture, certainly [there's] taboo and stigma associated with it, and consequently women may be waiting for someone else to bring it up, rather than struggling for a way to bring it up themselves.

"Women may believe urinary incontinence is 'part and parcel' of childbearing or ageing."

That belief - along with the apparent reluctance by health professionals to ask about urinary incontinence - left women suffering in silence, when there were effective treatments available, says Prof Hay-Smiths.

Health professionals had many opportunities to ask about women's "pelvic health" during consultations for contraception, cervical smears and gynaecological symptoms, she says.

As part of the sexual and reproductive health survey, women aged under 75 years were asked two questions about the frequency - daily, weekly, monthly, and amount - ranging from "a few drops" to "enough to wet the floor" - of incontinence.

Of the 2472 women with any incontinence, 41 per cent had this less than monthly, 44 per cent of them experienced this weekly, and 15 per cent daily.

While it was most common in women aged 50 and over, incontinence was also prevalent in those aged 16-29 (21 per cent).

"As our population ages, this means there will be more people with this condition; if this need isn't met then that creates further inequity in addressing the health needs of women," says Prof Hay-Smith.

"In addition, if urinary incontinence is not addressed in women under 75 years and these high rates continue, or increase after 75 years, then there are many more implications for older persons' health services."

Managing urinary incontinence with products was also a substantial economic and environmental cost, she says.

Depending on the cause, treatment did not always involve drugs or surgery.

"For many people it can be prevented, or mild symptoms can be cured, with the use of something like pelvic floor muscle training. It's clear from the evidence it's a very effective intervention."

Other people may not be aware that certain drinks could be irritating their bladders, or they could benefit from advice on how to ensure their bladders were "properly emptied".

While there was no link between incontinence and ethnicity, Prof Hay-Smith says Māori women were likely to suffer more from lack of access to care and living in areas without continence services.

"If you look at data like this, which suggests so many women are affected by this, that calls into question the organisation and resourcing in the health system to help women address that health need.

"This is just one of many issues in terms of health system organisation that is contributing to inequity in terms of women's quality of life."