Married at First Sight (MAFS) left viewers devastated this week as cast member Kristina Goodsell shone a light on her ongoing battle with a debilitating disorder. Breaking down in tears, the 31-year-old explained it was like ‘the worst feeling ever’ where everything feels ‘dark and horrible’, even when you try to fight it.

Kristina’s disorder is what’s known as PMDD – or Premenstrual Dysphoric Disorder. It refers to a number of extreme symptoms just one in 20 women experience in the seven to 10 days before their periods, according to the University of the West of Scotland.

For some, this may include intensified mood swings, depression, anxiety and feelings of worthlessness in addition to frequent or sudden tearfulness. Research suggests that one in every three people with PMDD attempt suicide.

On the physical side, many sufferers also experience headaches, bloating, muscle pain and problems sleeping too. Dr Gareth Nye, a Senior Lecturer at Chester Medical School ( @dr.gareth.nye ), told GetSurrey: “PMDD or Premenstrual Dysphoric Disorder is a disorder closely linked to a woman’s menstrual period and is very similar to premenstrual syndrome but symptoms have a much greater impact on day to day lives of sufferers.

“Patients tend to experience more mood altering symptoms on top of the physical ones with PMDD and may experience mood swings, irritability, depression or a lack of interest in day to day activities or lack of concentration. It may impact sleep and you may feel tired or even have panic attacks.”

Worryingly, Dr Nye believes that PMDD currently remains largely understudied, which may mean that countless cases are being overlooked. “It is largely undiagnosed for two major reasons,” he continued.

“First is a lack of understanding from medical professionals about the condition and the impact it may have. Secondly, it may be due to the woman herself not realising her experiences are not normal and can be treated and managed. We see many female centred conditions falling into these brackets.

“The menopause, for example, can be quite severe for some however women may just assume it’s normal.” While the cause of PMDD is largely unknown, some suggest it may be related to hormonal differences or even past physical or mental trauma.

For a ‘successful diagnosis’, Dr Nye said that a woman would usually need to have at least ‘five symptoms’ of PMDD – even if they show only for a short window in the menstrual cycle.

So, if you’re concerned you may have PMDD, it’s always worth logging your symptoms throughout the month and showing this to a doctor. Dr Nye added: “These changes make day to day life during this time extremely difficult and it may result in changes in work or home life.

“It can become more of an issue if support networks or employers do not understand the severity of the condition.” If you think you may have PMDD, it’s important to visit a GP for further examinations.