LONDON - Women are ignoring a potential key symptom of cancer by not getting an unexpected vaginal bleed checked out by a doctor, a charity has warned.

The Eve Appeal has found 8 in 10 women wouldn't visit a doctor with unexpected vaginal bleeding despite it being key gynaecological cancer symptom.

The charity, which polled 3,000 women, found almost three-quarters (72%) were not taught at school about how to spot when something is wrong with their periods.

And while 85% of respondents said they feel comfortable talking about periods with their family and friends, 80% said they would not seek medical attention for an unexpected vaginal bleed.

But abnormal bleeding is a key symptom of three out of the five gynaecological cancers - womb, cervical and vaginal - which together affect around 13,000 women each year.

While abnormal bleeding is easy to spot, the charity says there are many reasons some women don't get it investigated including a lack of awareness that it could be a symptom, embarrassment, fear of attending the GP surgery, or difficulties in getting to the GP.

Others simply see unexpected bleeding as "just one of those things".

But to mark Gynaecological Cancer Awareness Month this September, the charity hopes to raise awareness of this "red flag" symptom, which can include bleeding in between periods, after sex, after the menopause or bleeding that is much heavier or more painful than what is normal for you.

Whilst it is important to note that the majority of people who experience any abnormal bleeding won't have cancer, awareness of the potential symptom can be critical for improving early diagnosis in these three cancers.

The Eve Appeal have partnered with the Royal College of Obstetricians and Gynaecologists to draw up a series of tips to help women notice abnormal vaginal bleeding as part of their Go Red campaign.

They suggest women should track their periods to build up a picture of what is normal for them so they can quickly and easily spot anything abnormal.

Some of the things they suggest looking out for include:

Very heavy and/or very painful periods.

Bloody discharge - while discharge is normal, look out for any pink, red or brown 'bloody' discharge.

Unusual menopause bleeding - While going through the menopause can mean some irregular bleeding, if any bleeding doesn't seem right you should seek medical advice.

Post-menopausal period - Once you have not had a period for 12 months you have gone through the menopause. Any vaginal bleeding after this is an abnormal bleed.

Bleeding after sex - most of the time it isn't something to worry about but it is worth getting checked.

Pain if you bleed during/after sex - Sex isn't supposed to be painful, so worth getting it checked.

Dr Sue Ward, consultant obstetrician and gynaecologist and vice president of the Royal College of Obstetricians and Gynaecologists, called for more "open conversations" among people about women's health, saying it could be life-changing.

"Medical professionals, women, and society, need to start having more open conversations about women's health, including abnormal bleeding and post-menopausal bleeding," she said.

"This needs to start in school and continue throughout a woman's life. Ultimately, sharing experiences and providing easy access to information about gynaecological cancers will help to save lives."

Athena Lamnisos, chief executive of The Eve Appeal, said there can be many reasons for bleeding that are not cancer, but women should get anything they are concerned about checked out.

She said: "There are lots of reasons for abnormal vaginal bleeding – it probably isn't cancer, but it should be ruled out.

"It's so worrying that women are quite literally sitting on symptoms. We want to make everyone aware of our key message and get bleeding checked."