Signs and symptoms
The main symptom of dysmenorrhea is pain concentrated in the lower abdomen or pelvis. It is also commonly felt in the right or left side of the abdomen. It may radiate to the thighs and lower back.Symptoms often co-occurring with menstrual pain include nausea and vomiting, diarrhea, headache, dizziness, disorientation, fainting and fatigue. Symptoms of dysmenorrhea often begin immediately after ovulation and can last until the end of menstruation. This is because dysmenorrhea is often associated with changes in hormonal levels in the body that occur with ovulation. In particular, prostaglandins induce abdominal contractions that can cause pain and gastrointestinal symptoms. The use of certain types of birth control pills can prevent the symptoms of dysmenorrhea because they stop ovulation from occurring. Dysmenorrhea is associated with increased pain sensitivity and heavy menstrual bleeding.For many women, primary dysmenorrhea gradually subsides in late second generation. Pregnancy has also been demonstrated to lessen the severity of dysmenorrhea, when menstruation resumes. However, dysmenorrhea can continue until menopause. 5–15% of women with dysmenorrhea experience symptoms severe enough to interfere with daily activities. Causes
Dysmenorrhea can be classified as either primary or secondary based on the absence or presence of an underlying cause. Primary dysmenorrhea occurs without an associated underlying condition, while secondary dysmenorrhea has a specific underlying cause, typically a condition that affects the uterus or other reproductive organs.Painful menstrual cramps that result from an excess of prostaglandin release are referred to as primary dysmenorrhea.
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.