Many young women are not attending smear tests because they are embarrassed about their bodies, a cancer charity has warned.
Jo’s Cervical Cancer Trust said it was concerned that body image issues, including perception of what is "normal," could be putting women’s lives in danger.
One in four eligible women (aged 25-64) do not currently take up their invitation for a smear test, rising to one in three among 25-29 year olds.
It is even as high as one in two in some areas of the UK.
The charity conducted a survey which found that more than a third of women (35%) are failing to get tested because of their body shape, while 34% were worried about the appearance of their vulva.
Concerns over smelling "normally" (38%) were also a factor.
The poll of women aged between 25 and 35 also found a third (31%) admitted they would not go if they had not waxed or shaved their bikini area.
But despite low screening attendance, almost every woman (94%) said they would have a free test to prevent cancer if one was available.
The charity is releasing the data at the start of Cervical Cancer Prevention Week and as it launches its smear test campaign #SmearForSmear.
It is also concerned that not enough is being done to increase attendance, with a third of local authorities and Clinical Commissioning Groups in England not having done so in the last year.
Lindsay was diagnosed with cervical cancer at 29 after ignoring invitations for a smear test.
She said: "I was too busy with a baby and a small child, working, and I didn’t like the thought of having to get naked in front of anyone I didn’t know.
"I don’t want other women to have to go through what I experienced, diagnosis and treatment was awful.
"I needed a radical hysterectomy and still struggle with some side effects of treatment today.
"Please don’t put off your smear test, the alternative is so much worse."
The charity’s chief executive, Robert Music, said: "Smear tests prevent 75% of cervical cancers so it is a big worry that so many young women, those who are most at risk of the disease, are unaware of the importance of attending.
"It is of further concern that body worries are contributing to non-attendance.
"Please don’t let unhappiness or uncertainty about your body stop you from attending what could be a life-saving test.
"Nurses are professionals who carry out millions of tests every year, they can play a big part in ensuring women are comfortable."
Cervical cancer is the most common cancer in women under 35, yet the poll of 2,017 women found three out of five (61%) were unaware they were in the most at-risk age group for the disease.
Just under 1,000 women die from cervical cancer every year in the UK.
Cancer minister Steve Brine said: "We must all take a stand against cancer, that’s why I’m pleased to support this campaign so we can continue to see cancer survival rates improve and more cases prevented.
"Lives can be saved if women book an appointment for cervical screening when invited."