Menstruation, often called a menstrual period or simply a period, is the discharge of blood and tissue from a woman’s uterine lining. This combination of blood and tissue is called menstrual blood or menstrual fluid. While it often appears that a great deal of blood is lost during menstruation, the average woman loses only three to six table spoons of blood to each period. A period generally lasts for three to five days, but can take as long as seven days.
Women may begin menstruating at any age between eight and sixteen, but the onset of menstruation, called menarche, most typically occurs around the age of eleven or twelve. The flow of the first period tends to be very light and often contains no more than a few drops of menstrual fluid.
After menarche, women continue to menstruate until menopause, when the body stops releasing ova or eggs. Menopause typically occurs around the age of fifty-one, but it may occur earlier for reasons such as surgery or an illness.
The Menstrual Cycle
Menstruation is part of a woman's menstrual cycle, also called the reproductive cycle. The menstrual cycle prepares the body for pregnancy, and is controlled by hormones. The cycle typically takes between twenty-eight and thirty days, but it is not abnormal for a woman’s cycle to take as few as twenty-two days or as many as thirty-five.
The menstrual cycle begins on the first day of a woman’s period and ends on the last day before her next period. After the fifth day of the reproductive cycle estrogen levels rise causing the lining of the uterus, called the endometrium, to grow.
Around the fourteenth day of the cycle, one of the ovaries releases an egg (or ovum); this process is called ovulation. At the same time the hormone progesterone increases, preparing the endometrium for pregnancy. At this point, if a sperm reaches the ovum, the fertilized ovum can attach itself to the uterine wall, causing pregnancy. If the ovum is not fertilized, it will dissolve or be reabsorbed into the woman's body.
If the ovum is not fertilized by around the twenty-eighth day of the cycle, the body sheds the endometrium through bleeding. The blood and tissue leaves the uterus through the cervix and is discharged through the vagina. This shedding of the endometrium is menstruation. Menstruation begins the cycle again. A woman is less likely to get pregnant while menstruating than at any other time in the cycle, but there is still a chance of pregnancy at this point, especially for women with irregular cycles.
Pre-menstrual Syndrome (PMS)
PMS affects as many as seventy-five percent of menstruating women. As the name implies, PMS generally occurs before a period and ends once menstruation begins. The most common symptoms of PMS include abdominal cramps, a bloated abdomen, headaches, breast tenderness, tiredness, mood swings, food-cravings, anxiety, weight gain, pain in the joints and muscles, difficulty concentrating, nausea and depression. Most women suffering from PMS only experience a few of these symptoms. When the symptoms of PMS are severe enough to be disabling, the condition is called pre-menstrual dysphoric disorder (PMDD). About seven percent of women have PMDD (MayoClinic).
The cause of PMS is not known for certain. However, there are theories regarding factors that may contribute to the syndrome. Symptoms seem to change in response to hormonal fluctuations, which suggests that cyclic hormone changes may be a major cause. Changes in levels of serotonin, a neurotransmitter involved in mood states, may also contribute to PMS. Certain aspects of diet also appear to effect PMS. Low levels of vitamins and minerals are responsible for some symptoms, and salty foods may contribute to PMS by causing water retention. Alcohol and caffeine may also contribute by negatively effecting ones mood and energy level.
There are several types of medications a doctor can prescribe for PMS. Non-steroidal anti-inflammatory drugs (NAIDS) such as Advil or Aleve can be used to relieve abdominal cramps and breast tenderness. Oral contraceptives alleviate PMS symptoms by stopping ovulation and hormone fluctuations. Medroxyprogesterone acetate (Depo-Provera) can also be used to temporarily stop ovulation in order to treat severe PMS or PMDD. Antidepressants such as Prozac and Zoloft can reduce PMS symptoms in many women. Antidepressants can be used in lower doses to treat PMS than are generally used to treat depression.
There are also ways to minimize the symptoms of PMS without the help of drugs. A hot water bottle on the abdomen can treat cramps. Regular exercise reduces some symptoms such as fatigue and depression. Reducing salt, sugar and caffeine in ones diet may help prevent PMS, as these substances contribute to some of the symptoms. Because PMS is linked to deficiencies in vitamins and minerals, taking vitamin and calcium supplements or eating foods rich in vitamins and minerals helps limit the symptoms of PMS.
A "menstrual cup" is made from non-absorbent material that can be inserted into the vagina, where it collects menstrual fluid. A menstrual cup can be used for up to twelve hours at a time. Menstrual cups have been in use at least since the 1930s, although a version of this device may have existed as early as the mid-1800s. Menstrual cups come in both re-usable and disposable form. Re-usable cups can be washed out after each use and used again. These cups may be preferable to women concerned about the environment. However, disposable cups are more convenient.
Menstrual pads, also called sanitary napkins, are strips of absorbent material worn inside the underwear to collect menstrual fluid. Some women prefer to use re-usable cloth pads, but disposable pads are more common. Disposable menstrual pads were invented during World War I. The earliest disposable pads were used by nurses working on the battle lines and were made from cellu-cotton, a fabric similar to gauze that was originally used to bandage wounds. After the war ended, Kotex began selling surplus cellu-cotton as menstrual pads.
Pads are available in different levels of thickness. Maxi pads are thicker, and mini pads are thinner. Thicker pads can absorb more fluid but may be less comfortable. A woman may prefer a thinner or thicker pad, depending on how heavy her flow is at any given time. Because flow often varies throughout the period, the same woman may want to have several types of pads available.
Panty liners, also called panty shields, are similar to pads but are shorter and thinner. Panty liners are worn on very light days, or as added protection in combination with a tampon.
Tampons are pieces of absorbent material inserted into the vagina to absorb menstrual fluid. Tampons have strings attached to them, to make them easier to remove, and usually come with plastic or cardboard applicators to make them easier to insert. Tampons were first invented in the thirties, although products similar to tampons were used in earlier times. Tampons are very comfortable when used correctly. If a tampon feels uncomfortable or even noticeable after insertion, it may not have been inserted correctly.
One should not use tampons that are more absorbent than necessary. Overly absorbent tampons put women at a greater risk for Toxic Shock Syndrome and can cause vaginal dryness and ulcerations. Signs that a tampon is probably too absorbent include vaginal dryness, difficulty removing the tampon, the tampon shredding, and lack of a need to change the tampon after several hours.
The meanings of tampon absorbency levels used to be determined by the manufacturer, but are now regulated by the Food & Drugs Administration (FDA). A tampon with junior absorbency holds six grams of fluid or less, a tampon with regular absorbency holds six to nine grams, a tampon with super absorbency holds nine to twelve grams, and a tampon with super plus absorbency holds twelve to fifteen grams.
Toxic Shock Syndrome (TSS)
Tampons have been linked to Toxic Shock Syndrome (TSS), a disease caused by the Staphylococcus aureus bacterium. While rare, TSS can be fatal. About half of all cases occur in women using tampons. However, the reason for this link is not yet known. The initial symptoms of TSS are similar to the flu. They include diarrhea, dizziness, fainting, bloodshot eyes, sore throat, sunburn-like rash and sudden high fever. One to two weeks after the initial symptoms appear the skin may begin to flake, particularly on the palms and the soles of the feet. Someone who experiences any of these symptoms while using tampons or shortly after using tampons should see a doctor immediately. If a tampon is still being used when the symptoms appear, it should be removed immediately. With treatment, patients generally recover from TSS within a few weeks.
To avoid TSS, one should not leave the same tampon in for more than eight hours at a time, and should use the tampon with the lowest level of absorbency necessary for her flow. Evidence indicates that women who use overly absorbent tampons are at a greater risk for TSS. Women younger than thirty are at a greater risk for TSS than older women. Women who use tampons are at a greater risk than women who use pads, but women who alternate between tampons and pans are at less risk than those who only use tampons.
The number of TSS cases in the U.S. has dropped dramatically in the past decade or so. There were 813 cases of TSS in 1980 and only three in 1998. The most likely reasons for this decline are the removal of tampons made of super absorbent materials from the market and more advanced FDA regulations of tampon absorbency.
Reasons a Period May be Late
Amenorrhea is the absence of a period, either in a woman over sixteen who has not yet started menstruating, or in a woman who once had regular periods but has stopped menstruating. The most common reason for a missed period is pregnancy. Other causes of amenorrhea include breast feeding, extreme weight loss, eating disorders, over-exercising, stress, hormonal problems, and problems with the reproductive organs.
In the young and middle aged, a late period does not necessarily indicate pregnancy or a disorder. Periods tend to be very irregular for the first few years of menstruation and may become irregular again as the woman approaches menopause.
Disorders Related to Menstruation
Sometimes painful periods indicate a disease or condition. One such condition is uterine fibroids. Uterine fibroids are non-cancerous tumors that can grow in the muscles of the uterus and sometimes cause pain during menstruation. Fibroids may require treatment if they cause pain or heavy bleeding, but they often cause no problems and therefore require no treatment. Uterine fibroids tend to shrink after menopause.
Another disease that can cause painful cramps is endometriosis. This condition causes the endometrium to grow somewhere outside of the uterus, usually in the abdominal cavity. When the body sheds the endometrium each month, the fluid has no way to exit the body. In addition to cramps, endometriosis can cause irritation and scar tissue in the area surrounding the endometrium, irregular bleeding, infertility, and pain during or after sex.