“My co-worker claimed she had severe morning sickness. But I found out she was lying.”

As Kate Middleton has shown, Hyperemesis Gravidarum is a very real and devastating thing. It’s a type of pregnancy sickness so severe that keeping up with normal day-to-day life becomes impossible.

It’s not your average nausea with the occasional bout of vomiting thrown in. It’s constant sickness. Not being able to keep anything down. Not being able to go out. Without medical help, it can be life-threatening.

When you hear someone has HG, you take it seriously. A woman recently posted to UK website Mumsnet about her colleague, who was 14 weeks pregnant and had so far taken off five weeks with HG, with another week of medical leave still to go.

Massive sympathy to her. But then the woman explained that she had been on Facebook and had seen some photos of her friend on holiday in Greece. The friend also happened to be friends with the colleague who was off work due to HG. That colleague was in most of the photos, “sunbathing, eating, swimming in the sea, playing volleyball”.

Pregnancy guru Rebecca Judd shares the honest piece of information she wishes she’d been told as a new mum. (Post continues after audio.)

“I’m gonna sound like a complete cow,” the woman wrote, “but I think she’s faking her sickness. She’s on full pay from work and we’re having to pay an agency temp to cover her work too.”

She posed the question: “Should I tell/show our boss?”

The response from women who had suffered HG made it pretty clear that anyone with the condition wouldn’t be playing volleyball on a Greek beach.

“I had hyperemesis,” one woman remembered. “It was diagnosed when I ended up in hospital on a drip. I couldn’t move without vomiting. I have never felt so ill in my life – it was awful. I missed a friend’s wedding as there’s no way I could have gone.”

As for whether the woman should dob in her colleague, plenty of people said yes.

“Take screenshots and show the boss,” one wrote. “People doing things like this are a big part of the reason why sick pay is s–t and women’s pregnancy symptoms are doubted, in my opinion. It’s her own fault.”

It’s certainly true that in the past, women with HG have sometimes struggled to make people realise just how serious the condition is. It’s quite uncommon, affecting somewhere between one and three per cent of pregnant women. Women who suffer it in one pregnancy are highly likely to suffer it in a later pregnancy, and women whose sisters suffered it are also at a massively increased risk.

Women with HG lose weight and become dehydrated. Most need hospitalisation. There are cases of women vomiting so violently that their retinas have become detached, their eardrums have burst, their ribs have fractured or their fingernails have fallen off. Before the 1950s, it was the leading cause of death in pregnancy.

A survey of women with HG showed that one in seven had terminated at least one pregnancy due to the condition.

So... no joking matter.

But the question remains. Would you dob in a colleague if you thought she was faking HG?

Let us know in the comments below.