If you're a single woman over 30 you might think it's a jungle out there.

But did you know there's actually a "man drought" on? Or that in some places those who don't have a partner are known as "leftover women"?

The loaded terminology and expectations have led to an unhealthy stigma from which women still struggle to break free, according to documentary maker Mariona Guiu.

Sorry, this video has expired Singled Out documentary trailer

Guiu realised there was a problem a few years ago when she felt sad at the thought of being single and couldn't pinpoint why.

"I was actually quite pissed off with being concerned because I thought, 'Why? I'm supposed to be happy, I have the life I've chosen'," she said.

"So I called my best friend … and we decided to explore and dig deeper on the issue."

The result is the documentary Singled Out, which tracks five single women across four countries — China, Turkey, Spain and Australia.

Melburnian Jules Gibson has been single for a few years now. ( Supplied: Singled Out )

Along the way Guiu said they discovered a key problem across all cultures was "messaging".

"There is actually two messages — the one that says you can do it all and the other one which is a bit more underlying that says that as a woman, you will be complete when you will be able to form a family, to have a permanent partner," she said.

Melbourne woman Jules Gibson features in the documentary and said she had grown accustomed to justifying her single existence.

"I've been single for about three years and every time we have a family gathering, someone will go, 'Ooh is there somebody special in your life?' Nope, no there is not," she said.

"I used to be a bit timid in my reaction and go, 'No, there isn't.'

"Whereas now, I probably just say that it is irrelevant whether I'm single or not. I'm happy. I'm doing lots of things with my life."

It's an experience many ABC readers have had.

I'm tired of being asked how I change the lightbulbs or fix a leaking tap without being married to a man — Alyssa Rain

Still single at 32 and my heterosexual married-with-two-kids Catholic cousin asked me at a family barbecue if it was because I am a lesbian — Rebecca Brown

I was single in my thirties and was told my "eggs would dry up". That was very hurtful at the time. I choose not to be with the wrong person — Sue Hall Ness

I was single until I was 35 … people would try to set me up with the reasoning, "You're single, he's single. So it'll have to work out." Really? I loved my single life — Roz Crowden

Guiu said while the stigma was the same across countries, it varied in how explicit it was.

In Shanghai, documentary participants Shu and Yang are subjected to the term "leftover women", which is used to characterise women who haven't settled down with a family as they get older.

Yang is a succesful lawyer who has her own law firm, and refuses to lower her standards just to find a man. ( Supplied: Singled Out )

"The funny thing is, though, both in China and Shanghai and in Istanbul, the pressure is very strong … but at least you can identify the enemy," Guiu said.

"Whereas in places like Barcelona or Melbourne, because we are told that everything is alright, when you feel bad for not having a partner you think that you might be a bit crazy."

Shu is an entrepreneur and says her anxieties about being single have reached boiling point. ( Supplied: Singled Out )

In Instanbul, Melek says in the documentary she is facing pressure from relatives to give up the single life and settle back in their home town.

While in Barcelona, Manu is making a final attempt at IVF to have a baby while remaining single.

Melek's father supported her lifestyle, but since his death her brother has begun to pressure her to settle down. ( Supplied: Singled Out )

Australia faces its own unique issues, with researchers on the documentary finding there is a "man drought" happening.

They found one in three women aged between 30 and 40 had no partner and there was only one man "available" for every five women.

Ms Gibson said she wasn't surprised to hear women struggled to find a suitable man in Australia.

Manu is 40 and has been single for several years. She is making one last attempt at IVF. ( Supplied: Singled Out )

She attributed part of the problem to another issue Singled Out identified: Women are more economically independent than ever before and yet the quality of male partners hadn't necessarily improved.

"I have met quite a few man-childs in my time in dating," she said.

"We're seeing more professional women who sort of basically have impressive lifestyle resumes and we're not really seeing men matching that."