Easy Guide To: Periods, PMS And The Menstrual Cycle

Menstruation Guides


Guide To Menstruation


What Is Menstruation?
What Is the Menstrual Cycle?
What Age Do Periods Start?
What Age Do They Stop?
What Is PMS?
Menstrual Problems
When Should I See a Doctor About My Periods?

In This Section:

Menstrual Cycle
PMS Treatment
Heavy Periods
Irregular Periods
Missed Periods
Painful Periods
Toxic Shock Syndrome

Related Topics

Yeast Infections
Urinary Tract Infections
Female Reproduction System

What Is Menstruation?

Menstruation is the monthly bleed a woman experiences which first starts at puberty and ends with menopause. It is known as TOM (Time of the Month) or periods. Each month the female body prepares for pregnancy. The wall of the uterus (womb) starts to thicken and the ovary releases an egg into the fallopian tube. If the egg meets a male sperm, fertilization takes place. Either way the egg continues and takes a few days to complete its journey to the womb to commence pregnancy. If the egg is not fertilized, the uterus lining begins to shed and bleeding commences (see how periods happen). The blood and materials which are discharged are known as menses. The cycle begins all over again when another egg in the ovary comes to maturity. Most women use menstrual pads, tampons or sponges (natural sponges which can be rinsed and reused) to absorb bleeding.

What Is the Menstrual Cycle?

The average monthly menstrual cycle lasts 28 days and is calculated from the first day of your last period to the first day of the next. That said, a normal cycle can last anywhere between 21 and 38 days. The menstrual bleed usually lasts between 3 and 7 days. Although it may feel like more, most women only lose about 4 to 6 tablespoons of blood during a monthly bleed. The discharge is red-brown in color.

What Age Do Periods Start?

A first period is also known as a menarche. In the United States the average age for a girl to have her menarche is twelve and a half. However, some girls start as young as 9 and others as late as 15. Generally a period starts about two years after the breasts first start to develop (known as puberty). Interestingly, one study showed that girls who had their first menstrual period after the age of 14 had a much lower risk of developing endometriosis in later life (pelvic pain which can affect up to 10 percent of women).

What Age Do They Stop?

Women over 35 may start to notice that their menstrual cycle shortens to less than 28 days. This is due to less progesterone (and eventually less estrogen) being produced by the body. When perimenopause begins, periods go through an irregular phase before bleeding stops altogether. When a woman's periods have stopped consecutively for 12 months, it is considered she has reached menopause (see our menopause guidelines). This can happen anytime after 45, and usually by 50.

What Is PMS?

Premenstrual syndrome (PMS) is also known as Premenstrual Tension (PMT). It is a term used to describe a cluster of symptoms a woman may experience in the lead up to and during her period. Approximately 90 percent of women experience PMS symptoms every month before their period. Symptoms usually start to disappear with the onset of bleeding. PMS encompasses a group of symptoms; in fact over 150 have been identified! Common symptoms include: tiredness, bloating, depression and irritation; as well as, difficulties sleeping, food cravings, reduced libido, lower back pain, nausea and breast tenderness. Many of the symptoms are also early signs of pregnancy, probably because fluctuations in the same hormones are involved. A more severe version of PMS is called PMDD (premenstrual dysphoric disorder) which is often treated with antidepressants. There are many self-help remedies for treating PMS, including aerobic exercise and an extra dosage of calcium, vitamin E, vitamin B6 and evening primrose supplements.

Menstrual Problems

The menstrual cycle is a highly complex process, regulated by even more complex hormones. From time to time, women experience menstrual problems, mainly in the form of missed, irregular, heavy or painful periods. Fortunately most menstruation disorders are minor issues and easy to treat.

Irregular Periods (Oligomenorrhea)

Irregular periods (medical term oligomenorrhea) are most common in the 5 years after menarche and again in perimenopausal women approaching menopause. In both instances irregularities are caused by hormone imbalances. Occasionally irregular periods can occur in women of any age due to external factors such as extreme dieting or exercise, stress or eating disorders. Occasionally however irregular periods can be caused by a hormone imbalance related to polycystic ovary syndrome.

Heavy Periods (Menorrhagia)

Prolonged heavy periods (medical term menorrhagia) do not necessarily cause a problem unless they lead to embarrassing leakages or cause anemia because of excessive blood loss. Soaking a pad or tampon every hour or bleeding for more than 7 days is considered a form of menorrhagia. A heavy period in a pregnant woman however is likely to indicate pregnancy complications such as a miscarriage. Menorrhagia is usually caused by a hormone imbalance and a doctor may recommend the contraceptive pill as treatment.

Absence Of Periods (Amenorrhea)

The most common reason for missed periods is pregnancy. Amenorrhea however is the absence of menstruation in non-pregnant women. In most cases amenorrhea is not a cause for concern; it can be prompted by stress, excessive exercise, illness or extreme weight loss. Another relatively common cause is PCOS, but this condition can be tested for (PCOS diagnosis). If you have missed more than 3 periods, and have ruled out pregnancy, ask your doctor to check for a hormone imbalance. You may be prescribed the contraceptive pill to restart your periods. Alternatively, there may be special occasions where you want to delay a period, see can I delay my period without taking the pill?

Painful Periods (Dysmenorrhea)

Primary dysmenorrhea is defined as painful periods involving cramps and darting pains in the lower abdomen which radiate down the hips, thighs and around the back. Other common symptoms include nausea, feeling constipated and/or bouts of diarrhea. Primary dysmenorrhea usually begins within a few years of menarche although most women who suffer painful periods find that their symptoms lessen by their mid 20s or after their first pregnancy. Secondary dysmenorrhea is when pain associated with periods is caused by another condition such as PID, uterine fibroids, endometriosis or ovarian cysts. Treatment requires treating the underlying disorder.

Breakthrough Bleeding (Metrorrhagia)

Breakthrough bleeding is when a woman has another bleed (or spotting) between menstrual cycles. Some women experience metrorrhagia regularly as a harmless part of ovulation. Mittel-schmetz is an acute tummy pain which happens around the time of ovulation and is regularly accompanied by spotting. Sometimes an IUD device or contraceptive pill can cause breakthrough bleeding. Where spotting or bleeding occurs out of the blue, possible underlying causes include vaginal tears caused by intercourse, endometriosis, uterine fibroids, ectopic pregnancy, PID, incomplete miscarriage and some cancers such as endometrial cancer and cervix cancer.

When Should I See a Doctor About My Periods?

1. If you have not started your periods 2 years after your breasts have started growing.
2. If you have not started menstruating by the age of 15.
3. If your periods suddenly become very irregular after more than at least a year of a regular cycle.
4. You experience unusual heavy bleeding which soaks a pad or tampon every hour - or your period lasts longer than 7 days.
5. If you feel nauseous or feverish after using a tampon. This could indicate toxic shock syndrome.
6. Your menstruation cycle is less than 21 days or more than 35 days on a regular basis.
7. You suspect you are pregnant, but you can also check this with a pregnancy test.

Interesting Fact
In ancient Egypt people believed that both boys and girls menstruated because by adolescence almost everyone suffered bleeding from the bladder caused by schistosomiasis. This condition causes chronic fatigue and eventually heart disease. If you have questions on this topic, see womens health questions. Or check our related questions:
When should my periods start?

  Other Useful Guides

Recommended Health Screenings For Women: List for all ages.
How The Female Body Works: Visual guide with pictures.
Reproductive System Disorders: Comparing gynecological symptoms.
Development Of The Female Body: Menarche to postmenopause.

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