This gene encodes a protein essential for the regulation of immunity and inflammation.15 While the mechanism of how it influences PD has yet to be discovered, it is assumed that possible mutations in IL1A or genes which interact with it impact the regulation of inflammation during menstruation. These mutations may therefore affect pain responses during menstruation which lead to the differing phenotypes associated with dysmenorrhea. Two additionally well studied SNPs which are suspected to contribute to PD were found in ZM1Z1 (the mutant allele called rs76518691) and NGF (the mutant allele called rs7523831). Both ZMIZ1 and NGF are associated with autoimmune responses and diseases, as well as pain response. The implication of these genes impacting Dysmenorrhea is significant as it suggests mutations which affect the immune system (specifically the inflammatory response) and pain response may also be a cause of primary dysmenorrhea. Mechanism
The underlying mechanism of primary dysmenorrhea is the contractions of the muscles of the uterus which induce a local ischemia.During an individuals menstrual cycle, the endometrium thickens in preparation for potential pregnancy. After ovulation, if the ovum is not fertilized and there is no pregnancy, the built-up uterine tissue is not needed and thus shed. Prostaglandins and leukotrienes are released during menstruation, due to the build up of omega-6 fatty acids. Release of prostaglandins and other inflammatory mediators in the uterus cause the uterus to contract and can result in systemic symptoms such as nausea, vomiting, bloating and headaches or migraines. Prostaglandins are thought to be a major factor in primary dysmenorrhea.
One study indicated that in nulliparous individuals with primary dysmenorrhea, the severity of menstrual pain decreased significantly after age 40.A survey in Norway showed that 14 percent of females between the ages of 20 to 35 experience symptoms so severe that they stay home from school or work. Among adolescent girls, dysmenorrhea is the leading cause of recurrent short-term school absence. References
External links

Dysmenorrhea at Curlie