Menstruation in women


The menstrual cycle is an essential process in women. It requires secretion of various many hormones, mot primarily, the ovarian hormones such as estrogen and progesterone controlled by the pituitary gland. Some of the other hormones such as luteinizing hormone [LH] and follicle-stimulating hormone [FSH]  also play a vital role in the menstrual cycle. The menstrual cycle is one of the primary indicators to prove whether women can reproduce or not. During menstruation, the inner surface of the uterus(Endometrium) becomes thick, well-nourished, and rich in endometrial hormones. The onset and the duration of menstrual cycle depending on the age of the women, general health status, nutritional status, lifestyle, history of major uterine defects, underlying hormonal disorders, past history of amenorrhea ( absence of menses), etc. The following table depicts a few basic characteristics of menstruation. However, a normal healthy woman attains her menstruation every 28 days once. An average girl/women bears her first cycle- menarche in the age of  12–15 years, however, some girls start their first cycle as early as eight years  The average age at which menarche begins slightly vary geographically. In India, it is about 13 years,   12.5 years in the United States, 12.7 in  Canada. The abrupt stoppage of menstrual cycles at the end of a woman's reproductive period is termed menopause and in most of the cases, this happen between 45-55 years. Menopause before age 45 is considered premature menopause. The first menstruation is called menarche, an indication of whether a woman is ready for fertilization, however, a menstrual cycle doesn`t always imply that she is completely prepared for fertilization. Instead, there are many other factors help in deciding the women`s ability to reproduce. In a healthy women, menstrual cycle happens every  28-31 days. Each cycle has 4 phases; menstrual phase, follicular phase, ovulation phase, and the luteal phase. Among all, the ovulation period is crucial for reproduction. Ovulation usually happens on the 14th day of the cycle in healthy women, however, it varies sometimes. Ideally, one ovum is released (ovulation) during the middle of each menstrual cycle but rarely they can be 2-3 ovum being released. Women generally feel signs and symptoms of menstruation in advance. Some of the symptoms are feeling aches in the lower abdomen, headaches, feverish like feeling, bloating, mood fluctuation, tiredness, acne,  craving for food, tenderness of breast tissues and diarrhoea. The following section explains in detail the 4 phases of menstruation.

Table of Contents

1. Introduction

2. Phases of menstruation 

     2.1  Menstrual phase

     2. 2 Follicular phase

     2. 3 Ovulation phase

     2.4 Luteal phase

3. Causes of irregular menstrual cycle



Phases of menstruation 

Phases of menstruation-image from wiki commons


1. Menstrual phase

This is the 1st phase in which the inner surface of the uterus ( endometrium )  shed away by losing its spongy, weakened blood-filled layers. This will last for 3-5 days but in some women with excessive bleeding, the phase can go up to 7 days. Menstruation is an indication of NO PREGNANCY  because bleeding is the sign of failure of fertilization. Amenorrhea is - the absence of menstruation is closely linked with stress, poor health, age of women over 35 years.

2. Follicular phase

2nd phase in which the primary follicles present in the ovary develops into fully matured Graafian follicles. This is driven by hormones, estrogen and progesterone help in supplying the nourishment to growing follicles. At the same time, the endometrium of the uterus undergoes self-regeneration through a process called proliferation. Follicular changes are also linked with the increased levels of pituitary hormones, other ovarian hormones, as well as the secretion of gonadotropin (LH and FSH), assist in stimulating the follicular development.

3. Ovulation phase

This is the crucial phase of fertilization as the ovum necessary for reproduction is released during this period. Both LH and FSH will attain a peak level in the middle of the cycle (at about 14th day) which result in the release of a matures egg. A drastic secretion of LH results in the rupture of the Graafian follicle and thereby release the ovum - ovulation.

4. Luteal phase

This is the post-ovulation phase in which the remaining parts of the Graafian follicle become corpus luteum. The corpus luteum secretes a large amount of progesterone essential for the maintenance of the endometrium. If the ovum fails to fertilize, the corpus luteum automatically degenerates which in turn result in the repetition of the cycle from the  1st phase. If the woman turns 45-50 years,  she loses the ability to menstruate as a result of the normal ageing and the physiological changes, this is known as menopause. Cyclic menstruation is an indicator of the normal reproductive phase and extends between menarche and menopause.


Causes of irregular menstrual cycle

Reproductive disorders are becoming very common closely linked with the fast-paced lifestyle, food, habits and the industrial pollutants. Menstrual disorders or just a part of the sexual disorders. In 72% of the women, the cycle occur on an average of every 30 days. Even if it extends up to 35 days, it is still normal. Some of the associated factors of amenorrhea( absence of menstruation) are intrauterine infections, anatomical and physiological diseases of reproductive system, ageing ( above 40), Eating disorders resulting in extreme weight loss or gain, eating disorders like anorexia nervosa, Polycystic ovary syndrome (PCOS), premature ovarian failure, pelvic inflammatory disease (PID) and fibroid uterus.




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