Menstrual Bleeding

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:

  • Seasons
  • Diet
  • Medications
  • Exercise levels
  • Travel
  • 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
  • Hypothyroid­ism
  • Ovarian cysts
  • Uterine fibroids

Chronic menorrhagia can lead to anemia, potentially affecting overall health. (See Symptoms of Anemia.)

Symptoms of Anemia

Heavy menstrual flow may result in anemia, a potentially serious medical condition characterized by a low number of red blood cells. An optimum level of red blood cells is essential to good health because they contain hemoglobin, the protein that carries oxygen to all the other cells in the body. Without enough oxygen, all normal body functions are compromised and may become debilitated if oxygen depletion continues.

Common anemia symptoms include:

  • Fatigue
  • Weakness
  • Dizziness
  • Lack of mental clarity
  • Headaches
  • Lack of coordination
  • Loss of appetite
  • Heartburn
  • Abdominal pain
  • Diarrhea
  • Pale or yellow skin
  • Brittle and/or ridged fingernails
  • Hair loss
  • Sore tongue
  • Tingling in extremities
  • Heart palpitations

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:

  • Stress
  • Nervousness
  • Ten­sion
  • 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.

Hormone Therapies

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.

Vitamin Supplements

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.

Alternative Treatments

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

Surgical Treatment

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.
  • Northrup C. Women’s Bodies, Women’s Wisdom. New York, NY: Bantam Books; 1998.

The information on this website is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding any condition or medication. Do not disregard professional medical advice or delay in seeking it because of something you have read on this site.

Print Friendly, PDF & Email