While the average life expectancy for a woman in the U.S. is roughly 84 years, nearly half of her adult life will be spent post-menopausal. Approximately 37.5 million women are either currently in menopause, or are fast approaching this time of great change.

Usually one of the first things a woman notices at this time is a difference in her menstrual cycle. This can leave many unanswered questions about timing and flow, and what to expect in the upcoming months and years.

Why is my menstrual cycle irregular?

Occasional irregular menstrual periods may occur for a number of different reasons including stress, illness, extreme changes in weight, or medical conditions such as, polycystic ovarian syndrome or endometriosis. Thyroid problems, fibroids, or clotting issues may also cause an irregular cycle.[2]

The most common cause of irregular menstrual periods however, involves perimenopause, the period of time before the actual cessation of menstruation.

What causes irregular menstruation in menopause?

When women menstruate normally, hormone levels involving estrogen and progesterone rise and fall throughout the month. Ovulation begins in the middle of the cycle, followed by the release of blood and tissue approximately 14 days later. During the menopausal transition when hormone levels are erratic, irregular bleeding and spotting may occur. In some months the menstrual period may be heavier and last longer, while in other months the period may be of shorter duration and much lighter. A woman in menopause may begin skipping periods altogether.

Menstrual irregularities may occur only sporadically at first, with an occasional lightening of the period or a lengthier period than normal.
Why has my menstrual flow changed in perimenopause?

Heavy periods are more common during the transition to menopause. This is because the loss of progesterone inhibits, once normal regulation of the growth of the endometrium, or uterine lining expelled through menstruation. As a result, the lining may become thicker before it is shed. This results in very heavy periods.[3]
Medical conditions including endometriosis and uterine fibroids may worsen at this time because both are fueled by estrogen.

How do I know if my period is abnormal?

A typical menstrual cycle begins the first day of menstruation where blood and tissue that line the uterus, break down and begin to be shed through the cervix. This bleeding generally lasts from 4 to 8 days. The blood and tissue build up in the uterus is created in preparation for a possible pregnancy. If pregnancy does not occur, estrogen and progesterone levels fall, signaling the release of the uterine lining. Normal periods occur every 28-31 days.[4]

While many women experience differences in their menstrual periods, there are some ways to determine irregularities.

Changes include:

Shortened intervals between periods

Irregularities in length
Menstruation may occur either more frequently or more infrequently
Monthly periods may be missed altogether
Irregular Flow
Blood flow may either increase or decrease
Blood clots may appear or increase in size
Changes in pain or discomfort may occur
Painful cramping may occur[5]

Pain/bleeding

Severe pain or bleeding that interferes with normal activities is not normal.

What is considered heavy bleeding during the menopause transition?

Symptoms of heavy bleeding during perimenopause may include:

Bleeding through pads or tampons every hour or two
Large blood clots bigger then the size of a quarter
Bleeding for more than eight days

Can I become pregnant while menstruation is irregular during the menopause transition?

Yes. While the chances of becoming pregnant are much slimmer now that hormone levels are in decline and periods are irregular, pregnancy is still possible.

How do I know when I have reached perimenopause?

Most women have their periods for about 40 years before entering the phase preceding actual menopause, referred to as perimenopause. Menstrual irregularity is usually one of the first things a woman notices during this important transition. The actual cessation of menstruation does not follow a pattern of slow and steady decline, but rather an erratic succession of stops and starts.[5]

This makes it hard to predict when the next period will begin and how heavy the flow will be.

Irregular periods due to perimenopause may last for up to 10 years, before the actual cessation of menstruation.

What other menopausal symptoms will I have along with menstrual irregularity?

In addition to menstrual irregularity, menopausal symptoms include hot flashes, night sweats, mood swings, vaginal dryness, low libido, and sleep difficulties. You may experience one or all of these complaints.[5]

What factors impact menstrual irregularity and premature menopause?

While a healthy reproductive system is most often indicated by regular menstruation, certain factors may contribute to menstrual irregularity and early menopause.

These include:

Smoking
Stress
Obesity

Research finds that women who currently smoke had an earlier mean menopausal age than ex-smokers or non-smokers. Current smokers had roughly a 1.14 lower average age at menopause than non-smokers. Smoking for a lifetime also coincided with early onset menopause. While less is known about the impact of stress and obesity, there appears to be some association between high cortisol levels and excess fatty tissue on hormones, aging and menopause.[1]

Will I stop menstruating completely once I have reached menopause?

That depends.

Menopause occurs once a woman has not had a menstrual period for a period of 12 consecutive months. For most women, menopause occurs between the ages of 45 and 55. The average age of menopause in the United States is 52.
Sometimes a single “rogue ovulation” occurs however, after the one-year period has passed. This may be harmless as long as it is an isolated incident. Women who undergo hormone therapy of combined estrogen and progesterone may also experience occasional spotting in the early months of treatment, or light monthly bleeding if on a cyclic hormone regimen. Age-related thinning of vaginal tissues, or uterine polyps may also be to blame for bleeding after menopause.[2]
Apart from these causes however, post-menopausal bleeding is not normal and should be investigated promptly. About 10% of women under these conditions are diagnosed with endometrial cancer of the uterine lining or endometrium. If discovered in its early stages, endometrial cancer is completely treatable.

Why should I keep track of my menstrual cycle?

If menstrual periods are irregular it is important to keep a diary of dates and any changes experienced, to share with your doctor.

What can I do to better track my menstrual cycle?

Keeping track of the menstrual period is easy.

Simply record on a calendar or in a diary:

• When bleeding begins
• How heavy the bleeding is on the heaviest days of bleeding
• Was the bleeding heavier or lighter than usual?
• The number of pads or tampons used each period
• Period symptoms including any pain or discomfort that interfered with normal daily activity
• The number of days the period lasts
• Whether the period was shorter or longer as compared to other months

Also, document the frequency of menopausal symptoms such as, headaches, hot flashes, night sweats, difficulty sleeping and weight gain.

It’s most important to find what’s normal for you and your body during this time. If you have questions or concerns with menstrual irregularity or menopause, contact your doctor for further information and answers.