Buttock cramps during your period happen because the uterus and the pelvic nerves share overlapping pain pathways. When the uterus contracts to shed its lining, pain signals travel through the pelvic nerve network and spread into the lower back, hips, and buttocks. This is called referred pain, meaning the pain is felt far from its actual source.
Prostaglandins are hormone-like chemicals the body releases to trigger uterine contractions during menstruation. Higher prostaglandin levels lead to stronger contractions and more widespread pelvic pain, including deep aching in the buttocks.
