Menstrual Bleeding: What’s “Normal”?
Thinking back to your first experience of menstrual bleeding, you may recall a host of emotions, possibly including fear or shame, or perhaps even pride, depending on how you were prepared for the coming of menses. In Women’s Bodies, Women’s Wisdom, Dr. Northrup explains that menstruating women in cultures from ages ago “were considered sacred” and “their dreams and visions were used to guide the tribe.” These early beliefs fostered a sense of pride as women prepared their young girls to be initiated into the rites of womanhood.
Somewhere along the line, a cultural shift began to occur, and menstrual bleeding became associated with more negative connotations. Harmful myths and beliefs began to foster a fear and humiliation regarding menstruation, feelings that some women still experience. Perhaps these women don’t realize that menstrual bleeding is a normal, healthy, cleansing process. Having a better understanding of this necessary bodily process may help more women replace those fears or humiliation with a sense of pride regarding this “rite of passage” and monthly celebration of their womanhood.
The “Normal” Process
One concern expressed by many women is that they don’t know what’s “normal” when they experience menstrual bleeding, so they fear the worst. In order to understand what is “normal” versus “abnormal” bleeding, you should have a good understanding of how and why menstruation occurs. This will help you determine what is “normal” for you, making it easier to identify any irregularity, and perhaps understand why your normal bleeding pattern has been disrupted.
Menstruation refers to the phase of the female reproductive cycle in which the body sheds the uterine lining (endometrium), if pregnancy does not occur. 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 uterine lining. The uterus cleanses itself by releasing the extra blood and tissue so that the buildup can recur the following month.” Thus, cyclical uterine shedding (i.e., menstrual bleeding) is a normal female body function that cleanses the uterus, preparing it for the next reproductive cycle.
Hormones Regulate the Menstrual Cycle
The buildup and shedding of the uterine lining is 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, the ovaries, and the uterus. The glands that produce the hormones directly involved in triggering the different phases of the menstrual cycle are the hypothalamus, the pituitary, and the ovaries, but other glands, including the adrenals and thyroid, also affect menstruation. According to Dr. Lark, “The initial trigger for the menstrual cycle comes from hormones produced by the hypothalamus.” The hypothalamus, which is a gland just above the pituitary near the base of the brain, regulates many basic bodily functions, including hunger, thirst, body temperature, and sleep patterns. It also signals the pituitary to begin producing its own hormones, which in turn stimulate all other glands in the body, including the ovaries, as well as the adrenals 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 around day 14 or 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, but Dr. Northrup believes that description of normal is too narrow. She finds 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,” during which they “lose about four tablespoons of blood.”
Rates of flow also vary considerably, whereby what one woman considers to be a “heavy” flow is light for another. In the Women’s Encyclopedia of Natural Medicine, Tori Hudson’s guideline is that a flow is too heavy if a woman saturates a super tampon or thick pad more often than every hour, for more than six to eight hours.
Given these 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 can more easily identify when potentially significant changes occur.
Menstrual changes other than timing and flow may also be significant when describing your “normal” cycle. For example, 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). These are the types of details that are helpful to note, in addition to a description of flow and the start and end dates.
“Normal” variations in the menstrual cycle often coincide with different stages of a woman’s life. During puberty, a young woman’s periods may be irregular while her body adjusts to balance the influx of hormones. During perimenopause, a woman’s periods again may become irregular, reflecting the change in her hormone balance as various hormone levels decline.
Normal bleeding patterns can also be disrupted by changes in the seasons, diet, medications, exercise levels, travel, or during times of family or emotional stress. Dr. Northrup states that “I continue to be amazed by how clearly menstrual cycles and bleeding are connected to the contexts of our lives. Abnormal uterine bleeding is nearly always connected to family issues in some way.”
Sometimes an irregularity in your menstrual cycle can be a normal reaction to an abnormal situation, such as the death of a loved one or an illness. Determining what is normal for you requires looking at the bigger picture—the context of your life—not just the timing of your last menstrual cycle.
As explained earlier, period regularity is primarily determined by a complex interaction between the brain (hypothalamus, pituitary gland, and temporal lobes), the ovaries, and the uterus. Because the hypothalamus is so sensitive to stress, any form of stress whether it is family stress, an illness or infection, or even too much exercise can hinder the hypothalamus’ ability to pass signals to the pituitary. The resulting imbalance of hormones disrupts the menstrual cycle, altering the bleeding pattern or flow.
Cigarette smoking, excessive alcohol consumption, poor nutritional habits, or anything that impairs liver function can also disrupt the pattern because the liver is responsible for breaking down the estrogen hormones. If the liver is not functioning properly, the increased levels of estrogens are likely to thicken the uterine lining and contribute to heavier bleeding.
Irregular or abnormal bleeding is a common cause for concern among women, and a frequent reason for scheduling an office visit. Any time uterine bleeding is unexpected, or unusually light or heavy, it is considered to be “abnormal,” even though there may be a logical explanation for it. Dr. Northrup contends that “Menstrual blood, especially when it comes at an unscheduled time, is a message. It carries wisdom of some kind.”
Abnormal bleeding can result from many different situations and conditions, some of which are unrelated to ovulation or menstruation. For example, unexpected bleeding can occur due to irritation from intercourse or an intrauterine device, or 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 tumor. Different forms of abnormal bleeding include the following:
- Irregular menstrual bleeding, which typically occurs at the beginning or end of a woman’s reproductive phase when hormones are in a state of flux, is fairly common. During these life phases (i.e., puberty and perimenopause), irregular bleeding is usually caused by insufficient levels of the estrogen hormones, resulting in no ovulation. The lack of ovulation means that there is no progesterone production during the second half of the menstrual cycle, resulting in no bleeding, or 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 “out of the blue” without any warning signals. Women who do not ovulate tend to have more irregular periods.
- Some women experience only occasional menstrual bleeding, such as once or twice per year. Known as oligomenorrhea, this type of irregularity is typically due to a pituitary malfunction or polycystic ovaries, but may also occur due to irritation from intercourse or an intrauterine device, or after stopping birth control pills. It could also signal a potential miscarriage or an ectopic pregnancy.
- Heavy menstrual bleeding, also known as menorrhagia, includes bleeding that is either too heavy or too fast, or moderate bleeding that occurs for an extended period of time. Large blood clots and midcycle spotting may also occur. Common causes include estrogen dominance, nutritional deficiencies, hypothyroidism, the use of intrauterine devices, ovarian cysts, and uterine fibroids. Chronic menorrhagia can lead to anemia, potentially affecting your overall health. (See Symptoms of Anemia .)
- A lack of menstrual bleeding is called amenorrhea, where 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 far more common than primary amenorrhea and refers to the condition whereby a woman stops menstruating after experiencing regular periods. The most common reason for missing a period is pregnancy. Other potential reasons include stress, nervousness, tension, emotional trauma, weight gain or loss, poor nutrition, excessive exercise, or prolonged use of birth control pills—all of which can disrupt the intricate hormone balance that is necessary for maintaining a regular bleeding cycle.
Treatments for Abnormal or Irregular Bleeding
The various forms of abnormal bleeding can often be treated to induce menses, regulate flow and/or alleviate symptoms. Depending on the root cause, typical treatment methods include drug and hormone therapies, vitamins and nutritional supplements, as well as alternative treatments such as herbal medicines and acupuncture, and surgery, usually as a last resort.
Drugs are often prescribed as an initial course of treatment, including:
- Over-the-counter or prescription non-steroidal anti-inflammatory drugs (NSAIDs), such as Motrin™, Ibuprofen, Naprosyn™ and Anaprox™. 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 also have potentially serious side-effects, and some women’s symptoms actually get worse with this treatment.
- Synthetic derivatives of testosterone such as Danazol™ or Danocrine™ suppress female hormone production and alter the metabolism of estrogens and progesterone, sometimes providing pain relief and reducing bleeding. Potential drawbacks include masculine side-effects and a recurrence of symptoms after stopping treatment.
- Gonadotropin-releasing hormone (GnRH) analogs such as Luron™ or Nafarelin™ also inhibit female hormone production and may reduce bleeding, oftentimes producing menopause-like symptoms.
Hormone therapies are also often prescribed to regulate the cycle and reduce blood flow. (Note that there are significant differences between “conventional” hormone therapies and “natural” hormone therapies that are biologically identical to those found in the human body.) Typical biologically identical hormone treatments include:
- Progesterone (sometimes combined with estrogen hormones, depending on the reason for the abnormal bleeding) helps prevent erratic periods and heavy bleeding. According to the research of Dr. Fitzpatrick and Dr. Good at the Mayo Clinic, progesterone therapy is effective in treating irregular bleeding, especially for women in perimenopause. Dr. Lark concurs 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, and women account for almost 90% of the hypothyroidism cases in the United States.
Vitamin supplements also help many women reduce or alleviate abnormal bleeding. Vitamin A “plays a significant role in the prevention of heavy menstrual bleeding,” according to Dr. Lark. Vitamin A supplements alleviated menorrhagia in 92% of the 71 patients in a study by Lithgow and Politzer. 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 sometimes called the “anti-stress” vitamin because it 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.
Alternative treatments, including 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. Dr. Northrup often 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 unblock qi or “life force energy” to improve reproductive organ or liver function.
Surgical treatment for the relief of abnormal bleeding is typically recommended only after other treatment approaches have proven to be unsuccessful, or if the known cause is a physical abnormality. Surgery 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 ablasion, 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.
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.
No matter which treatment you choose, it is important to continue working with your healthcare practitioner to monitor ongoing treatment results and adjust your treatment accordingly.
- Women’s Bodies, Women’s Wisdom by Christiane Northrup, MD; Bantam Books; New York, NY; 1998.
- Heavy Menstrual Flow & Anemia Self Help Book, Third Edition, by Susan M. Lark, MD; Celestial Arts; Berkeley, CA; 1999.
- Women’s Encyclopedia of Natural Medicine by Tori Hudson, ND; Keats Publishing; Los Angeles, CA; 1999.
- Alternative Medicine Guide to Women’s Health 1 by Burton Goldberg and the Editors of Alternative Medicine; Future Medicine Publishing, Inc.; Tiburon, CA; 1998.
- “Micronized progesterone: clinical indications and comparison with current treatments” by Lorraine A. Fitzpatrick, MD, and Andrew Good, MD, in Fertility and Sterility, Vol. 72, No. 3, September 1999.
- “Vitamin A in the Treatment of Menorrhagia” by D. M. Lithgow, BSC, MB, BCH, FBCS; and W.M. Politzer, MD, in SA Medical Journal; February 1977.
- It’s Your Body: A Women’s Guide to Gynecology by Niels Lauersen, MD, and Steven Whitney; Putnam Publishing Group; New York, NY; 1993.
- 8 Weeks to Vibrant Health by Hyla Cass, MD, and Kathleen Barnes; McGraw-Hill; New York, NY; 2004.