Painful periods increase sensitivity to pain throughout the month

A brain imaging study carried out at Oxford University shows that period pain is associated with differences in the way the brain processes pain, and that these differences persist throughout a woman's menstrual cycle.

Accordingly, women with painful periods show increased sensitivity to pain throughout their cycles, even when there is no background period pain.

The findings are published in the journal Pain.

The Oxford researchers in the Nuffield Department of Obstetrics and Gynaecology and the Centre for Functional Magnetic Resonance Imaging of the Brain applied hot pads to the inner arm and abdomen of 12 women with painful periods (but who were otherwise healthy), and 12 women without, while they were in an MRI scanner.

Their brain's responses to this painful stimulus were compared at three different points in the women's menstrual cycles.

The team found that the group of women with painful periods were more sensitive to the hot pads – the pads didn't have to be turned up as far to get the same reports of pain.The brain imaging data revealed that women who experience period pain showed changes in activity in brain areas known to be involved in the pain response.