Primary dysmenorrhea

Introduction Primary dysmenorrhoea is a functional dysmenorrhea. Dysmenorrhea refers to menstrual pain, often spasmodic, concentrated in the lower abdomen, other symptoms include headache, fatigue, dizziness, nausea, vomiting, diarrhea, low back pain. It is a very common condition among young women. Primary dysmenorrhea is not associated with significant pelvic organic disease. There is abdominal pain in the lower abdomen, and there is general malaise. In severe cases, it affects daily life.

Cause

1. Abnormal uterine contractions The occurrence of primary dysmenorrhea is associated with increased uterine tension and excessive spasmodic contraction caused by increased uterine muscle activity. During normal menstrual period, the basal tension in the uterine cavity is <1.33 kPa, the pressure during uterine contraction does not exceed 16 kPa, and the contraction is coordinated. The frequency is 3 to 4 times/10 min. During dysmenorrhea, the basal tension in the uterine cavity increases, the pressure during uterine contraction exceeds 16-20 kPa, the contraction frequency increases, and it becomes uncoordinated or arrhythmic contraction. Due to the abnormal contraction of the uterus, the blood flow to the uterus is reduced, causing uterine ischemia, leading to dysmenorrhea.

2. Prostaglandin or leukotriene synthesis and release

The endometrium is an important part of the synthesis of prostaglandins. There is much evidence that uterine synthesis and release of PG increase. It is an important cause of primary dysmenorrhea. PGF2a and thromboxane A2 can stimulate excessive contraction of the uterus, resulting in decreased uterine blood flow. Intravenous or intrauterine input of PGF2a can manifest symptoms of primary dysmenorrhea, including related systemic symptoms such as nausea, vomiting, diarrhea, and headache.

3. The role of vasopressin and oxytocin Vasopressin, another important cause of dysmenorrhea, has been confirmed by many studies. The level of vasopressin is elevated in women with primary dysmenorrhea. This hormone can also cause contraction of the smooth muscles of the myometrium and arterial wall, and the blood flow of the uterus is reduced. The intravenous injection of hypertonic saline can increase the secretion of vasopressin. Increase uterine contractions and aggravate symptoms of dysmenorrhea. Estrogen stimulates the release of vasopressin from the pituitary gland, which is counteracted by progesterone. Under normal circumstances, plasma vasopressin levels are highest during ovulation, and the luteal phase declines health search until the menstrual period. In women with primary dysmenorrhea, the estrogen level in the late luteal phase is abnormally elevated, so the vasopressin level is 2 to 5 times higher than that in the normal person on the first day of the menstrual period, causing excessive contraction of the uterus and ischemia.

4. Other

(1) Cervical stenosis: In the past, it was considered that the uterine cervix was not produced, which caused the intrauterine pressure to rise. The menstrual blood flowed back into the pelvis and stimulated the pelvic nerve endings, causing pain. Menstrual menstrual blood flow was more common and did not necessarily cause dysmenorrhea.

(2) Other peptides and autonomic nervous system: Endothelin and norepinephrine can also cause uterine muscle and uterine vasoconstriction, leading to dysmenorrhea. The autonomic nervous system (choline, adrenergic) peptide nerves can also affect the uterus and blood vessels. Anterior sacral nerve resection can treat dysmenorrhea, reduce postpartum dysmenorrhea in term pregnancy, and is also associated with a significant reduction in autonomic nerve fibers in the uterus.

(3) Immune system: Recently, some scholars have studied the changes of immune cells and immune responses in patients with dysmenorrhea for the first time. It is found that the mitogen-induced lymphocyte proliferative response is significantly decreased in the 26th day of the cycle, and the monocyte - in the blood on the third day of the cycle. Increased levels of endorphins suggest that dysmenorrhea is a recurrent disease that creates a physical and psychological stress that leads to changes in the immune response.

an examination

Related inspection

Vaginal secretion examination gynecological examination

Laboratory inspection:

Secretory examination, hormone level check.

Other auxiliary inspections:

B-ultrasound, laparoscopic, hysteroscopy, uterine tubal iodine angiography.

Diagnosis of primary dysmenorrhea, gynecological examination without positive signs for the diagnosis of primary dysmenorrhea, mainly to rule out the existence of pelvic organic lesions. Take a complete medical history, do a detailed physical examination (especially gynecological examination), exclude endometriosis, adenomyosis, pelvic inflammation.

Differential diagnosis

Differential diagnosis

1. Ovarian tumor pedicle torsion can be found in different sizes of tumors, the symptoms are mostly limited to the disease side.

2. Ovarian corpus callosum rupture abdominal pain is often accompanied by nausea and convenience, the symptoms are biased to one side.

3. Appendicitis metastatic abdominal pain and one side of the body is heavier.

Diagnosis of primary dysmenorrhea, gynecological examination without positive signs for the diagnosis of primary dysmenorrhea, mainly to rule out the existence of pelvic organic lesions. Take a complete medical history, do a detailed physical examination (especially gynecological examination), exclude endometriosis, adenomyosis, pelvic inflammation.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.