by Dr. Panshak John Chanshilip

Jun 15, 2020


Menstruation, which is the shedding of the upper layers of the endometrium(inside of the womb) occurring with blood loss, normally takes...

Menstruation has wrongly been believed to be monthly bleeding from the vagina seen at the end of the cycle. It's wrong because menstruation is the presence of REGULAR vaginal bleeding seen at the BEGINNING of the menstrual cycle. Remember it is regular bleeding but not constant bleeding.
A cycle simple means something or a pattern that is repeated. So it is expected that menstrual cycle will have series of events that are repeated.
A normal menstrual cycle length is counted from the first day of one menstrual period to the first day of the next period and it ranges from 21-35 days. That is to say that it may be normal to menstruate twice in a month depending on the individual's usual cycle length. It is important to know your cycle length so that you will detect any abnormality when it occurs.
Menstruation, which is the shedding of the upper layers of the endometrium(inside of the womb) occurring with blood loss, normally takes within 1-7 days. Longer duration is abnormal.
Two important events occur during a menstrual cycle and these events are regulated by hormones (oestrogen, progesterone, Luteinizing Hormone-LH, Follicle Stimulating Hormone-FSH, Gonadotropin Releasing Hormone-GnRH) and other regulators.

  1. Menstruation
  2. Ovulation

Immediately after menstruation the ovaries, stimulated by hormones, begin maturation of some eggs(ova) in which one or sometimes two dominate the race and are released at ovulation. So ovulation is the release of matured egg(ovum) and it usually occurs at about the 14th day from the beginning of the cycle. It may cause some pain when it occurs. The released egg stays in the fallopian tube for about 1-2 days and begins to degenerate when no sperm fertilizes it.

Inside the womb immediately after menstruation, the shedded layer begins to regrow in preparation for an anticipated baby which supposedly should come during the fertile period (ovulation). When there is no fertilization of the egg by a sperm and the egg degenerates, the prepared "bed" for the implantation of the fertilized egg degenerates and is shed off with blood during menstruation. Then maturation of new sets of eggs begin in the ovaries again after completion of menstruation and the cycle repeats itself.

It is worthy of mention that every female child is born with complete number of eggs. New ones are not produced rather the already formed eggs begin to enter maturation in turns from puberty up till menopause (when the egg store is depleted).
Note also that the blood of menstruation does not clot due to certain mechanisms that prevent it from clotting. So it is abnormal when you see blood clot in menses.

Lastly, when an egg is fertilized by a sperm cell and pregnancy sets in, the woman does not menstruate again until about 6-8weeks after she has delivered.


1.What causes menstrual cramps and why does the intensity of pain vary amongst individuals?

Answer:  Mentrual cramp is felt when the womb contracts in order to shed the inner linings/layers. During the menstrual period there is an increased release of prostaglandins(chemicals which stimulate contraction of the womb) by the body and the same thing occurs at a higher rate during delivery. So the more prostaglandins one secretes the more the pain.
2. Can a short or long menstrual cycle length be corrected?

Answer: Yes it can be corrected by the appropriate use of hormonal pills. This is also dependent on the cause of the abnormality. Some may require other forms of therapy. Continue to follow this series of discussion on menstruation subsequently and learn more.

3. Calculation of ovulation?

​​​​Answer: first know your cycle length. Then subtract 14 days from your cycle length. Whatever figure you get, start counting from the current/present date, including the present date, until you exhaust that number. The date you get after counting off the number is your ovulation date. Two days before the ovulation and the ovulation day are your most fertile periods.

4. Why is menstrual cycle length not consistent in all women and why does age at first menstruation vary?
Answer: So many factors can cause variation in these ranging from genetics, environmental factors, socioeconomic status, obesity, level of physical activity, malnutrition, psychological factors.

Let us know that you have an understanding of this article by answering this question:
A girl who has 24 days cycle length and usually mentruates for 3 days in each cycle saw her period twice in may (at the beginning and end of the month). Is that abnormal or normal? Drop your answer on our social media handles using the handles below.
Follow subsequent articles on this series to understand the disorders or abnormalities of the menstrual cycle and also the "safe periods" in the cycle.