What is a menstrual cycle? – Menstrual cycle refers to the sequence of events in women that culminate into menstruation. It starts from the first day of one menses until the beginning of the next. An average cycle is about 28 days but may normally range between 21 to 35 days. Its main aim is to prepare the body for the possibility of pregnancy each month.
The menstrual cycle of an individual woman is unique to her. Menstrual cycles may also vary in the same person from time to time.
Menstruation refers to the monthly vaginal bleeding in a woman. The bleeding results from the shedding of the lining of the uterus (womb) earlier prepared for pregnancy. Once pregnancy fails to occur that month, the lining of the uterus, prepared to accommodate and nurture pregnancy, is discarded as blood, which trickles out through the cervix and out of the vagina as menstruation / menses / menstrual flow etc.
The lining of the uterus is prepared through the interaction of different hormones (biological chemicals in the body) produced from the brain to the ovaries. This interaction makes the lining of the uterus thickened in order to allow an embryo (developing baby) find comfortable place to grow should pregnancy occur in that cycle. In the absence of pregnancy, the prepared endometrium is discarded and preparation for another one starts.
Menstruation usually starts at around the age of 12 years on the average. However, menstruation may start as early as 8 years or as late as 16 years. Menstruation is usually the end of the spectrum of pubertal development, which consists of accelerated growth, breast, pubic and axillary hair development.
Normal menstrual flow may range from one to seven days. The duration of flow is unique to individuals, though there may be slight variation of one to two days in the same individual.
Normal menstrual flow should not contain blood clots (thick blood). This is because nature has provided a way of preventing menstrual blood from clotting by providing anti-clot mechanism for the expected normal quantity of menstrual blood. However, when the flow is excessive and overwhelms this natural anti-clot mechanism, the blood begins to clot.
So, menstrual blood clot is an indication of excessive menstrual flow. Also, menstrual blood flow should not overwhelm the menstrual pad by spilling over. This may be subjective as different women may change their pads at different intervals for different reasons.
The menstrual cycle has four phases which can be broadly grouped into two: The follicular phase, where follicles are recruited to produce eggs, and the ovulation phase, when the eggs mature and are released to be fertilized, make the first part while the luteal phase, which is the phase of maturation of the lining of the womb in order to accommodate fertilized eggs, and the menstrual phase, when the lining sheds if fertilization of the eggs released fails to take place, make the second part.
It is usual for menstrual cycle length to vary slightly in the same woman. That is a woman with 28-day cycle may sometimes have 29-day, 30-day, 27-day, 26-day etc cycles. This is still within the acceptable limit of the individual woman. Any of these variations not more than five days from the original cycle length is considered normal.
This normal variation is usually due to variation in the days of ovulation in the first half of the cycle. Anything exceeding the specified limits is considered abnormal and may require doctor’s attention.
The following symptoms may be felt by women before or during menses:
These symptoms have been associated with high level of the hormone progesterone which occurs towards the beginning of menstruation.
Most of the symptoms accompanying menstruation are mild and self-limiting. As such, they may not need any form of treatment. However, in some cases, they may cause significant discomfort as to warrant treatment. Menstrual cramps tend to be the most disturbing of all the symptoms. This can be reduced or treated by: