Mensturation - Facts

The menstrual cycle is a recurring cycle of physiological changes in the females of some animal species that is associated with reproductive fertility.

This article concentrates on the menstrual cycle as it occurs in human beings.

Only human beings and the great apes experience a true menstrual cycle. Most placental mammals experience estrous instead. The menstrual cycle is under the control of the reproductive hormone system and is necessary for reproduction. In women, menstrual cycles occur typically on a monthly basis between puberty and menopause.

During the menstrual cycle, the sexually mature female body builds up the lining of the uterus with gradually increasing amounts of oestrogen, and when this hormone reaches a critical level, estradiol is produced, and shortly thereafterward there is the stimulation of the ovaries with Follicle Stimulating Hormone (FSH), and luteinizing hormone (LH). Follicles begin developing, and within a few days one "matures" into an ovum or egg. The ovary then releases this egg, (or occasionally two, which might result in dizygotic, or fraternal/non-identical, twins) at the time of ovulation. (Identical twins form from a single egg, as a result of the zygote splitting.) The lining of the uterus, the endometrium, peaks shortly there afterward in a synchronised fashion. After ovulation, this lining changes to prepare for potential conception and implantation of the fertilized egg to establish a pregnancy. The hormone progesterone rises after ovulation, and peaks shortly thereafter.

Women show considerable variation in the lengths of their menstrual cycles, and the length of the menstrual cycle differs in different animals (see below).

While cycle length may vary, 28 days is generally taken as representative of the average ovulatory cycle in women. Convention uses the onset of menstrual bleeding to mark the beginning of the cycle, so the first day of bleeding is called "Cycle Day one".

One can divide the menstrual cycle into four phases:

Eumenorrhea denotes normal, regular menstruation that lasts for a few days (usually 3 to 5 days, but anywhere from 2 to 7 days is considered normal.[3] The average blood loss during menstruation is 35 millilitres with 10-80 mL considered normal;[4] many women also notice shed endometrium lining that appears as tissue mixed with the blood. An enzyme called plasmin — contained in the endometrium — tends to inhibit the blood from clotting. Because of this blood loss, women have higher dietary requirements for iron than do males to prevent iron deficiency. Many women experience uterine cramps, also referred to as dysmenorrhea, during this time. A vast industry has grown to provide sanitary products to help women to manage their menses.

Through the influence of a rise in Follicle stimulating hormone (FSH), five to seven tertiary-stage ovarian follicles are recruited for entry into the menstrual cycle. These follicles, that have been growing for the better part of a year in a process known as folliculogenesis, compete with each other for dominance. In a signal cascade kicked off by luteinizing hormone (LH), the follicles secrete estradiol, a steroid that acts to inhibit pituitary secretion of FSH. With diminished FSH supply comes a slowing in growth that eventually leads to follicle death, known as atresia. The largest follicle secretes inhibin that serves as a finishing blow to less competent follicles by further suppressing FSH. This dominant follicle continues growing, forms a bulge near the surface of the ovary, and soon becomes competent to ovulate.

The follicles also secrete estrogens (of which estradiol is a member). Estrogens initiate the formation of a new layer of endometrium in the uterus, histologically identified as the proliferative endometrium. If fertilized, the embryo will implant itself within this hospitable flesh.

In many women, various intense sensations brought about by the involved hormones and by cramping of the uterus can precede or accompany menstruation. Stronger sensations may include significant menstrual pain (dysmenorrhea), abdominal pain, migraine headaches, depression and emotional sensitivity, and changes in sex drive. Diarrhea or loose stools are common for the first few days of a woman's period.[citation needed] Breast discomfort caused by premenstrual water retention is very common. The sensations experienced vary from woman to woman and from cycle to cycle.

While some women allow their menses to flow freely, most women prefer to use some external means to absorb or catch their menses to prevent soiling their clothes. There are a number of different methods available.

Disposable items:

• Sanitary napkins (Sanitary towels) or pads - Somewhat rectangular pieces of material worn in the underpants to absorb menstrual flow, often with "wings," pieces that fold around the panties, and/or an adhesive backing to hold the pad in place. Disposable synthetic pads are made of wood pulp or synthetic products, usually with a plastic lining and bleached. Some sanitary napkins, particularly older styles, are held in place by a belt-like apparatus, instead of adhesive or wings.
• Tampons - Disposable wads of treated rayon/cotton blends or all-cotton fleece, usually bleached, that are inserted into the vagina to absorb menstrual flow.
• Padettes - Disposable wads of treated rayon/cotton blend fleece that are placed within the inner labia to absorb menstrual flow.
• Disposable menstrual cups -- A firm, flexible cup-shaped device worn inside the vagina to catch menstrual flow. Disposable cups are made of soft plastic (like Instead).

Reusable items:

• Reusable cloth pads are made of cotton (often organic), terrycloth, or flannel, and may be handsewn (from material or reused old clothes and towels) or storebought.
• Menstrual cups - A firm, flexible bell-shaped device worn inside the vagina to catch menstrual flow. Reusable versions include rubber or silcone cups (like the Keeper, DivaCup, Lunette, and Mooncup).
• Sea sponges - Natural sponges, worn internally like a tampon to absorb menstrual flow.
• Padded panties - Reuseable cloth (usually cotton) underwear with extra absorbent layers sewn in to absorb flow. (like Lunapads)
• Blanket, towel - Large reuseable piece of cloth, most often used at night, placed between legs to absorb menstrual flow.

In addition to products to contain the menstrual flow, pharmaceutical companies likewise provide products — commonly non-steroidal anti-inflammatory drugs (NSAIDs) — to relieve menstrual cramps. Some herbs, such as dong quai, raspberry leaf and crampbark, are also claimed to relieve menstrual pain