A Healthy and Necessary Function in Women’s Health
Menstrual bleeding is a normal, healthy, and cleansing process. However, one concern expressed by many women is that they don’t know what is “normal” when they experience menstrual bleeding. Understanding how and why menstruation occurs helps clarify what is “normal” versus “abnormal” bleeding. This will help determine what is “normal” for you, making it easier to notice irregularities and identify what has disrupted the normal bleeding pattern.
The Process of Menstruation
Menstruation is the phase of the female reproductive cycle in which the body sheds the uterine lining (endometrium) if pregnancy does not occur. Cyclical uterine shedding (i.e., menstrual bleeding) cleanses the uterus, preparing it for the next reproductive cycle. In Heavy Menstrual Flow & Anemia, Dr. Susan Lark explains menstruation as:
Each month the uterus prepares a thick, blood-rich cushion to nourish and house a fertilized egg. If conception occurs, the endometrium becomes the placenta. If pregnancy does not occur, the egg doesn’t implant in the uterus and the body doesn’t need the extra buildup of the uterine lining. The uterus cleanses itself by releasing the extra blood and tissue so that the buildup can recur the following month.
Hormones Regulate the Menstrual Cycle
The buildup and shedding of the uterine lining are controlled by fluctuations in hormones, primarily the estrogens and progesterone. These hormonal fluctuations are the result of an elaborate feedback system among different parts of the brain, ovaries, and uterus. The glands that produce the hormones that are directly involved in triggering the different phases of the menstrual cycle are the hypothalamus, the pituitary, and the ovaries; other glands, including the thyroid and adrenal glands, also affect menstruation.
According to Dr. Lark, “The initial trigger for the menstrual cycle comes from hormones produced by the hypothalamus.” The hypothalamus is a gland just above the pituitary near the base of the brain and regulates many basic bodily functions, including hunger, thirst, body temperature, and sleep patterns. It also signals the pituitary to begin producing hormones, which stimulates all other glands in the body, including the ovaries, adrenal glands, and thyroid.
During the first two weeks of a normal cycle (immediately following the previous menstruation), estrogen triggers the endometrium to gradually rebuild itself by increasing the number of blood vessels and forming an interconnecting fiber mesh that thickens the uterine lining. The pituitary releases follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which target the ovaries. Upon receiving this signal (usually mid-cycle), the ovaries begin ovulation.
At this point, the follicles begin producing more of the estrogens (as well as some progesterone), which triggers the ripening and release of an egg for potential fertilization as it travels down the fallopian tube to the uterus. The follicle that produced that month’s egg becomes further stimulated by LH and transforms into the corpus luteum, which secretes more progesterone, triggering the uterine lining blood vessels to coil, and becoming swollen and thick with mucous in preparation for a fertilized egg. If fertilization occurs, the egg implants on the uterine wall and the corpus luteum continues secreting progesterone. If fertilization does not occur, progesterone levels decrease, triggering the corpus luteum and uterine lining to break down, and menstruation begins.
Sufficient levels of progesterone and the estrogen hormones are needed to maintain a healthy, regular bleeding cycle. One of the estrogen hormones, estradiol, reaches its peak during the first half of the cycle, while progesterone peaks after mid-cycle when ovulation has occurred. The timing of those peaks is one aspect of regulating the menstrual cycle.
Variations of “Normal”
Most women are taught that the “normal” menstrual cycle is 28 days with three to five days of bleeding. However, Dr. Christiane Northrup believes that description of “normal” is too narrow, finding that typical cycles range anywhere from 24 to 35 days and that bleeding duration also varies. Dr. Hyla Cass agrees, noting that “most women’s periods last two to seven days.”
Rates of flow also vary considerably; what one woman considers a heavy flow is light for another. Given the wide variations of a “normal” cycle, it is important to determine what is normal for you by paying attention to your menstrual patterns and flow, so that you may more easily identify when potentially significant changes occur. Menstrual changes other than timing and flow may be significant when describing “normal” menstrual cycle:
- Some women observe a clear discharge similar to raw egg white approximately 12 to 16 days after the first day of their last menstrual period (sometimes referred to as “fertile flow” because it usually indicates ovulation has occurred)
- Some women notice a distinct odor that occurs only during menstruation, often as a result of increased sweating in the pubic area
- Many women report periodic spotting (light bleeding between cycles or instead of cycles) or clotting (shedding thick or stringy blood clots)
Variations in the menstrual cycle often coincide with different stages of a woman’s life. A young woman’s periods may be irregular during puberty while her body adjusts to balance the hormonal influx. A woman’s periods may become irregular again leading up to menopause, reflecting the change in her hormone balance as various hormone levels decrease.
Determining what is normal requires looking at the bigger picture—the context of your life—not just the timing of your last menstrual cycle. Bleeding patterns may be disrupted by changes in:
- Exercise levels
- Family or emotional stress
Sometimes an irregularity in the menstrual cycle is a normal reaction to an abnormal situation, such as illness or the death of a loved one.
Menstrual regularity is primarily determined by a complex interaction between the brain (hypothalamus, pituitary gland, and temporal lobes), the ovaries, and the uterus. The hypothalamus is so sensitive to stress that any form of stress may hinder its ability to pass signals to the pituitary. The resulting imbalance of hormones disrupts the menstrual cycle, altering the bleeding pattern or flow.
Anything that impairs liver function may also disrupt menstrual patterns because the liver is responsible for breaking down estrogen hormones. Without proper liver function, increased levels of estrogens may thicken the uterine lining and contribute to heavier bleeding. Factors that affect liver function include cigarette smoking, excessive alcohol consumption, and poor nutritional habits.
Common Menstrual Irregularities
Abnormal bleeding may result from many different situations and conditions, some of which are unrelated to ovulation or menstruation. For example, unexpected bleeding may occur soon after stopping birth control pills. Abnormal bleeding may also signal a potential miscarriage or an ectopic pregnancy, or indicate the presence of a cyst, polyp, or fibroid tumors.
Irregular menstrual bleeding
Irregular menstrual bleeding is fairly common. It typically occurs during times of hormonal changes in a woman’s life. During life phases such as puberty and perimenopause, irregular bleeding is usually caused by insufficient levels of the estrogen hormones, resulting in no ovulation.
Women who do not ovulate tend to have more irregular periods. The lack of ovulation means that there is no progesterone production during the second half of the menstrual cycle, resulting in no bleeding, spotting, or irregular bleeding patterns. Women who don’t ovulate usually don’t experience premenstrual symptoms and are therefore often surprised when they get a period without any warning signals.
Occasional Menstrual Bleeding
Some women may experience only occasional menstrual bleeding, such as once or twice per year. Known as oligomenorrhea, this irregularity is often due to a pituitary malfunction or polycystic ovary syndrome (PCOS), but may also occur due to irritation from intercourse or after stopping birth control pills. It might also signal a potential miscarriage or an ectopic pregnancy.
Heavy Menstrual Bleeding
Also known as menorrhagia, heavy menstrual bleeding includes bleeding that is either too heavy or too fast, or moderate bleeding that occurs for an extended time. Large blood clots and mid-cycle spotting may also occur. Common causes may include:
- Estrogen dominance
- Nutritional deficiencies
- Ovarian cysts
- Uterine fibroids
Chronic menorrhagia can lead to anemia, potentially affecting overall health. (See Symptoms of Anemia.)
No Menstrual Bleeding
Amenorrhea is the lack of menstrual bleeding and is divided into two types: primary amenorrhea and secondary amenorrhea. Primary amenorrhea refers to a woman who is past puberty but has never experienced menstrual bleeding. Common causes include a hormone imbalance, or congenital abnormalities of the vagina, uterus, or ovaries.
Secondary amenorrhea is more common than primary amenorrhea and refers to the condition when a woman stops menstruating after experiencing regular periods. The most common reason for missing a period is pregnancy. Other potential reasons include:
- Emotional trauma
- Weight gain or loss
- Poor nutrition
- Excessive exercise
- Prolonged use of birth control pills
These factors may disrupt the hormone balance necessary to maintain a regular bleeding cycle.
Treatments for Abnormal or Irregular Bleeding
Depending on the underlying cause, the various forms of abnormal bleeding may often be treated to induce menses, regulate flow, and/or alleviate symptoms. Common treatment methods include drug and hormone therapies, vitamins, and nutritional supplements. Alternative treatment options include herbal medicines, acupuncture, and surgery.
The initial treatment of abnormal menstrual bleeding typically involves medications:
- Over-the-counter or prescription non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. For some women, these drugs provide pain relief and/or help reduce menstrual flow. However, as with any drug, there may be unintended side-effects.
- Low-dose birth control pills that include synthetic replacements for estrogens and progesterone. While this approach may help to regulate some women’s periods, these drugs have potentially serious side-effects. Additionally, some women’s symptoms worsen with this treatment.
- Synthetic derivatives of testosterone suppress female hormone production and alter the metabolism of estrogens and progesterone. This sometimes provides pain relief and reduces bleeding. Potential drawbacks include masculine side-effects and a recurrence of symptoms after stopping treatment.
- Gonadotropin-releasing hormone (GnRH) analogs such as Nafarelin also inhibit female hormone production and may reduce bleeding, often producing menopause-like symptoms.
Hormonal replacement therapies are often prescribed to regulate the cycle and reduce blood flow. However, there are significant differences between “conventional” hormone therapies using synthetic hormones and “natural” hormone therapies using bioidentical hormones that are identical to those produced by the human body. This means that not all forms of hormone therapy are equally effective or well-tolerated. Typical bioidentical hormone treatments include:
- Progesterone helps prevent erratic periods and heavy bleeding and is sometimes combined with estrogen hormones, depending on the reason for the abnormal bleeding. According to researchers at Mayo Clinic, progesterone therapy is effective in treating irregular bleeding, especially for women in perimenopause. Dr. Lark concurs with their findings, noting that progesterone is “the most effective medical treatment available for women in menopause transition.”
- Thyroid therapy is often prescribed because hypothyroidism (low thyroid function) is a common cause of heavy menstrual bleeding. Women account for almost 90% of the hypothyroidism cases in the United States. Replenishing thyroid hormone levels may be used to correct this imbalance, resolving the root cause of the abnormal bleeding.
Many women use vitamin supplements to reduce or alleviate abnormal bleeding:
- Vitamin A “plays a significant role in the prevention of heavy menstrual bleeding,” according to Dr. Lark. One study of 71 test subjects indicated that vitamin A supplements alleviated menorrhagia in 92% of the patients.
- The B vitamins, especially B12 and folic acid, are essential to liver function and help prevent (or reverse) anemia. During stress, the B vitamins are more easily depleted, which explains why any kind of stress contributes to abnormal bleeding.
- Vitamin C is important to adrenal function, which controls the stress response. Vitamin C also increases iron absorption to help prevent anemia.
- Vitamin E is necessary for ovulation and helps reduce excess levels of estrogens.
Dietary changes, herbal medicine, and acupuncture are also used to reduce or eliminate abnormal bleeding problems:
- In the Alternative Medicine Guide, Burton Goldberg describes reversing amenorrhea with dietary changes and stress reduction
- Tori Hudson, a naturopathic physician, promotes the use of herbal remedies such as uterine tonics in treating abnormal bleeding and uterine dysfunction
- Northrup suggests alternative approaches such as daily exercise to help control excess estrogens, and castor oil packs to boost liver function and help balance hormone levels
- Many women report having symptom relief after acupuncture when it is used to improve reproductive organ or liver function
In general, surgery is only used to alleviate abnormal bleeding after other treatment approaches have proved unsuccessful or if the known cause is a physical abnormality. It is usually considered as the last resort because of the physical and emotional stress involved. Surgical procedures sometimes used to treat abnormal bleeding include:
- Endometrial biopsy, primarily to rule out cancer
- Dilatation and curettage (D&C) to remove the uterine lining
- Endometrial ablation, described by Dr. Lark as “a laser or electro-surgical technique to essentially render the lining of the uterus inactive”
- Myomectomy to remove fibroid tumors while preserving the uterus
- Hysterectomy to remove all or some of the reproductive organs
Irregular or abnormal bleeding is a common concern among women and is a frequent reason for scheduling a visit to their healthcare practitioner. Any time uterine bleeding is unexpected, or unusually light or heavy, it is considered to be “abnormal,” even if there may be a logical explanation.
Given the variety of potential reasons for abnormal bleeding, it is best to discuss any irregularities in your bleeding pattern or flow with your healthcare practitioner. Accurately reporting the details of your bleeding patterns will help your practitioner properly diagnose your condition and identify appropriate treatment options to fit your individual health needs. No matter which treatment you choose, it is important to continue working with your healthcare practitioner to monitor ongoing symptoms and adjust treatment accordingly.
- Cass H, Barnes K. 8 Weeks to Vibrant Health. New York, NY: McGraw-Hill; 2004.
- Fitzpatrick LA, Good A. Micronized progesterone: clinical indications and comparison with current treatments. Fertil Steril. 1999 Sep;72(3):389-97.
- Goldberg B, et al. Alternative Medicine Guide to Women’s Health 1. Tiburon, CA: Future Medicine Publishing, Inc.; 1998.
- Hudson T. Women’s Encyclopedia of Natural Medicine. Los Angeles, CA: Keats Publishing; 1999.
- Lark SM. Heavy Menstrual Flow & Anemia Self Help Book. Third Ed. Berkeley, CA: Celestial Arts; 1999.
- Lauersen N, Whitney S. It’s Your Body: A Women’s Guide to Gynecology. New York, NY: Putnam Publishing Group; 1993.
- Lithgow DM, Politzer WM. Vitamin A in the Treatment of Menorrhagia. S Afr Med J. 1977 May 14;51(20):694-5.
- McCormick K. Feminine Bleeding: What’s “Normal”? Connections. Women’s International Pharmacy; 2005.
- Northrup C. Women’s Bodies, Women’s Wisdom. New York, NY: Bantam Books; 1998.