Painful periods are costing women around nine days of lost productivity at work each year, researchers have calculated.
The study, published in the British Medical Journal, found women are coming into work even though they are unwell and are therefore underperforming.
More than eight in 10 women reported working or studying while suffering with pain or a mood disorder, and said they were less productive because of it.
Researchers in the Netherlands surveyed almost 33,000 women aged between 15 and 45.
Menstrual symptoms prompted nearly a third of the women to visit their family doctor and around one in seven to see a gynaecologist.
Overall, women went into work when they were unwell an average of 23 days out of the working or study year.
Based on their symptoms affecting a third of the duration of their day, researchers calculated that this amounted to almost nine days of lost productivity each year.
Sometimes the symptoms were so intense women needed to take time off work or school, with one in seven doing so. Nearly 3.5% said this happened almost every menstrual cycle.
When women called in sick because of period pains, only one in five told their employer or school the real reason for their absence, according to the findings reported by the Daily Mail.
Around two thirds of women said they wished they had the option of flexible work or school hours when they are on their period.
Corresponding author Dr Theodoor Nieboer said it is likely that the real impact of menstruation-related symptoms is underestimated in the general population.
“Despite being almost two decades into the 21st century, discussions about symptoms may still be rather taboo,” he added.