PMDD (Premenstrual Dysphoric Disorder) is an extreme form of premenstrual syndrome (PMS) where women can fall into severe depression, anxiety, suicidal thoughts and feelings of being out of control in the run up to their period.
Treatments can include hormone treatments and, in rare cases and if recommended by a doctor, the removal of the ovaries.
It affects an estimated 1 in 20 women of reproductive age and last year was recognised by the World Health Organization.
As part of BBC Research, around 4,000 women shared their experiences of the condition.
Reporter: Daniela Relph
Producer: Georgie Bevan
Filming: Ross Miklaszewicz
Editing: Tony Smith
If you’ve been affected by any issues raised in this piece, visit BBC Action Line.