Pain during menstruation, is a common problem among the teenage girls. More than 70% of teenagers and 30 to 50% of menstruating women suffer from varying degrees of discomfort at the time of menstruation. The severe incapacitating type, which interferes with a woman’s daily activities, affects only about 5 to 15% of the population.
In this post, I have discussed primary dysmenorrhoea in detail including types of dysmenorrhoea, its clinical manifestations and causes.
What is Dysmenorrhoea?
Dysmenorrhoea can be defined as painful menstruation of sufficient magnitude, so as to incapacitate day to day activities.
Types of Dysmenorrhoea
On the basis of pathogenesis, dysmenorrhoea can be of following types-
1. Primary Dysmenorrhoea
One that is not associated with any identifiable pelvic pathology. Pain is a result of biochemical derangement.
2. Secondary Dysmenorrhoea
One associated with presence of organic pelvic pathology, i.e. fibroids, adenomyosis, PID, endometriosis etc.
Clinical Varieties of Dysmenorrhoea
Depending on the clinical manifestation, dysmenorrhoea can be classified as:
1. Spasmodic Dysmenorrhoea
Spasmodic Dysmenorrhoea manifests as cramping pains, generally most pronounced on the 1st and 2nd day of menstruation. Seen in case of primary dysmenorrhoea.
2. Congestive Dysmenorrhoea
Congestive Dysmenorrhoea manifests as increasing pelvic discomfort and pelvic pain a few days before menses begin. Thereafter, the patient rapidly experiences relief in her symptoms. Commonly seen in PID or pelvic endometriosis.
3. Membranous Dysmenorrhoea
A rare variety, manifested as severe uterine cramps, accompanied by the passage of a cast or partial cast of the uterine cavity.
4. Dysmenorrhoea due to IUD
Another cause of dysmenorrhoea, that should be considered, is cramping due to the presence of an Intra Uterine Contraceptive Device.
Causes of Primary Dysmenorrhoea
Mechanism of initiation of pain in primary dysmenorrhoea is difficult to establish. However, the pain is often related to dysrhythmic uterine contractions and uterine hypoxia, most probable causes of which are:
1. Increased levels of prostaglandins in the menstrual fluid.
In ovulatory cycles, (P.S. - Primary Dysmenorrhoea is almost always confined to ovulatory cycles) prostaglandins are synthesized from the secretory endometrium prior to menstruation; with maximum production during shedding of the endometrium.
Increased production of the prostaglandins or increased sensitivity of the myometrium to the normal production of prostaglandins leads to:
- Increased myometrial contraction, with or without dysrhythmia.
- Ischemia (angina) of the myometrium.
2. Psychosomatic factor
Pain may occur due to tension and anxiety during adolescence.
3. Abnormal anatomical and functional aspect of uterus
- Stenosis at internal os makes it difficult for menstrual blood to escape, which leads to strong uterine contractions causing pain.
- In case of septate or bicornuate uterus, pain is due to unequal muscular contractions.
- Cervix fails to dilate, when uterus contracts to expel menstrual blood.
- Inadequate expulsive force, in case of uterine hypoplasia.
- Imbalance in autonomic nervous control of uterine muscle.
Over activity of the sympathetic, may lead to hyper tonicity of the circular fibers of isthmus and internal os. The relief of pain, following dilatation of the cervix, or following vaginal delivery, may be explained by the damage of the adrenergic neurons, which fail to regenerate.
4. Role of vasopressin
There is increased vasopressin release during menstruation in women with primary dysmenorrhoea. Vasopressin increases prostaglandin synthesis and also increases myometrial activity directly.
5. Role of endothelins & leucotrienes
Endothelins and leucotrienes are vasoconstrictors and stimulate myometrial contractions.
Clinical Maifestations of Primary Dysmenorrhoea
Primary dysmenorrhoea occurs in ovulatory cycles; hence it makes its appearance a few years after menarche. It is most intense on the 1st day of menses and progressively lessens with menstrual flow. It often lessens with passage of time and after child birth. Clinical features include-
1. Local Symptoms
Spasmodic pain confined to lower abdomen; may radiate to the back and medial aspect of thighs.
2. Systemic Symptoms
Systemic discomforts like nausea, vomiting, fatigue, diarrhea and headache may be associated. It may be accompanied by vasomotor changes causing pallor, cold sweats and occasional fainting. Rarely, syncope and prolapse may occur in severe cases.
3. Physical Examination
Physical examination does not reveal any significant pelvic disease. When the patient is symptomatic, she has generalized pelvic tenderness, perhaps more so in the area of the uterus than in the adjoining areas.
