Is your menstrual flow abnormal?

Last week I wrote about irregular menstrual cycle patterns, and what they might mean from a stress physiology perspective. Tracking will help you identify what is happening with your menstrual cycle, but interpretation of those patterns requires an understanding of what is considered normal vs abnormal.

This post is part of a series covering frequently asked questions about your menstrual cycle, with an emphasis on abnormal presentation. What a normal period should look and feel like was discussed in a previous post. In this post we will cover abnormal menstrual flow patterns which should be distinguished from non-menstrual flow patterns. The term abnormal uterine bleeding encompasses both.

Menstrual bleeding: heavy periods, light periods, prolonged bleeding, menstrual clots

Non-menstrual bleeding: mid-cycle bleeding, premenstrual bleeding, bleeding after sex

I want to emphasize that this post is not meant to replace medical advice from a doctor or other healthcare provider. There are certainly times when it is strongly advised to see your doctor. For example:

  1. No periods
  2. Cycles that are shorter than 21 days or longer than 35 days
  3. Bleeding for more than seven days
  4. Losing more than 80 mL of menstrual fluid in one period
  5. Period pain so bad that you cannot do your normal activities
  6. Pain between periods, especially if it is severe
  7. Bad-smelling vaginal discharge
  8. Bleeding between periods that is not ovulation spotting

Excerpt From: Briden, Lara. Period Repair Manual: Natural Treatment for Better Hormones and Better Periods.

Let’s start with a definition. Abnormal uterine bleeding (AUB) is bleeding that is abnormal in duration, volume, frequency, or regularity; and has been present for the majority of the previous 6 months (McCance KL & Huether SE, 2019). Outdated definitions remain commonly used and include terms like: menometrorrhagia, menorrhagia, menorrhea, polymenorrhea, metrorrhagia, and hypermenorrhea. In some cases, I will refer to these terms. Current terminology describes AUB as chronic, acute, inter-menstrual and heavy. Studies show that ten to thirty percent of women will experience AUB in their lifetime (McCance KL & Huether SE, 2019).

2. Menstrual flow

Do you have heavy periods?

The outdated medical term for heavy periods is menorrhagia. According to Medscape, “Menorrhagia is defined as menstruation at regular cycle intervals but with excessive flow and duration and is one of the most common gynecologic complaints in contemporary gynecology”(Julia A Shaw et al., 2018).

Two important pieces of information in that definition: 1. excessive flow AND duration; and 2. regular cycle intervals.

1. Excessive flow AND duration. Normal menstruation length is 3-7 days. Normal blood loss is 25-80 ml. To visualize this, one soaked normal-sized tampon or pad holds a teaspoon (5 ml) of blood. Depending on the model, a menstrual cup holds about 2 tbsp (30 ml) of blood. What type of tampon or pad (liner vs overnight) was used and if it was soaked may add some insight, since quantity is a very subjective issue.

Taken together, this means that heavy bleeding is flow that lasts longer than 7 days and blood loss greater than 80ml.

2. Regular cycle intervals. Menorrhagia is defined as heavy menstruation at regular cycle intervals. Heavy menstrual bleeding should be distinguished from other bleeding patterns because of the lengthy list of possible causes. The workup will be different for other diagnoses, so it’s important that you know your cycle length. If you don’t already do so, please start tracking your cycle. For example, menometrorrhagia is the medical term used to describe frequent and excessive flow. It is a combination of heavy menstrual bleeding and irregular bleeding; therefore, factors contributing to both must be considered.

This leads me to the next point. The workup.

Heavy bleeding requires a thorough patient history, physical examination (including pelvic exam), imaging studies (if indicated) and appropriate lab studies. Pregnancy is the most common cause of irregular bleeding in women of reproductive age and the first diagnosis that should be excluded before further testing or treatment. Depending on your signs and symptoms, your doctor will want to rule out underlying medical conditions, including bleeding disorders. This is strongly considered when someone has any of the following:

  1. Menorrhagia since menarche
  2. Family history of bleeding disorders
  3. Personal history of 1 or more of the following: (1) Notable bruising without known injury, (2) bleeding of the oral cavity or gastrointestinal tract without an obvious lesion, or (3) bleeding from the nose of more than 10 minutes’ duration, possibly requiring packing or cautery (Julia A Shaw et al., 2018).

Causes are numerous and often unknown. Factors contributing to heavy bleeding can be sorted into four categories: organic (eg bleeding disorders), endocrinologic (eg PCOS), anatomic (eg fibroids), and iatrogenic (eg IUDs) – medical term that means it was caused by medical examination or treatment (Julia A Shaw et al., 2018). If the workup does not provide any clues to the cause, a diagnosis of dysfunctional uterine bleeding (DUB) is given. Most cases of DUB are secondary to anovulation. I wrote extensively about anovulatory cycles in this post. In DUB, cycles are usually irregular.

Once this workup is complete, treatment should be tailored to the underlying cause, your health history, your health needs, and desired health outcomes. Treatment must also address the specific part of the menstrual cycle perceived to be abnormal, (ie, cycle length, quantity of bleeding, presence of clots and their size).

After a proper workup, if the cause is still unknown or if medical therapy fails to alleviate symptoms, iron-deficiency anemia as a result of blood loss must be considered and addressed. Iron studies will help with this assessment. Breathlessness, easy bruising, palpitations and fatigue may be experienced.

People who do not respond to medical therapy may be offered surgical intervention to control the menorrhagia. For some people this may be the right option. However, it is at this point (before surgery) that a naturopathic doctor may recommend functional lab testing, like a month-long salivary or dried urinary hormone test. This type of cycle mapping provides the full picture of a woman’s hormonal pattern throughout her menstrual cycle. The two main hormones that are said to impact menstruation are estrogen and progesterone. These hormones regulate the cycle. Unopposed estrogen (due to lower than optimal progesterone levels or estrogen excess) can result in heavy bleeding because estrogen allows the endometrium to proliferate and thicken. Progesterone keeps that growth in check. But why would this imbalance occur? A number of factors contribute to hormonal imbalance. The problem with standard serum lab testing is that it only tests reproductive hormones on a single day or two days (day 3 and/or day 21) of your cycle. But what if everything appears normal at that specific point in time? This is where functional medicine testing can help. Once the hormonal pattern is fully elucidated, symptoms can be correlated with hormone levels.

Here is a DUTCH cycle mapping sample report from Precision Analytical.


A complete picture of your cycle in graph format (fun, I know) will allow for a more accurate and comprehensive treatment program specific to your situation and needs. This is what individualized medicine is all about. In my practice, I do not charge a mark-up on these tests. I charge what the lab charges me. In many cases, I need this information. I will never order unnecessary testing for financial gain. This is something that I feel very strongly about, so I want to be transparent with my approach here. If I order functional lab testing, it is because I need it. Not because I want to make an extra buck or two.

Recap: So are your periods heavy? Ask yourself:

  • Do you pass clots?
  • Do you have to change menstrual products overnight?
  • Do you experience “flooding” where the blood seems to pour out?
  • Does the bleeding interfere with your normal activities? Consider your physical, emotional, and social quality of life.
  • Has the heavy bleeding made you anemic or low in iron and red blood cells?

These are some of the questions I ask my patients as part of a menstrual history when heavy bleeding is suspected or reported. Common and concerning symptoms around menstruation should be openly discussed with your healthcare provider. There is a lot of information that can be obtained from a thorough health history.

Do you have menstrual clots?

One feature of heavy bleeding is passing clots (lumps of blood) during menstruation. When menstrual flow is heavy, your body’s clotting system is activated. The clotting or coagulation system is a group of plasma proteins that, when activated sequentially, forms a blood clot. However, if this system doesn’t have time to keep up with the flow (because of heavy bleeding), you will see menstrual clots. A few clots are fine, but if you regularly see clots larger than a quarter, then please see your doctor.

Are your periods light?

If normal menstrual fluid loss is 25-80 ml, it stands to reason that light menstruation is less than 25 ml. Again, quantity is a very subjective issue so be sure to track your menstrual product use.

If you have determined that your periods are light, then the next important step is determining if you’re ovulating. If you’re not ovulating, then it’s not a true period. It’s an anovulatory bleed. You must restore ovulation. Menstruation is part of a cycle. Remove any part of that cycle, and you can’t progress from one step to the next. The fertility awareness method (FAM) is a way to track your physical signs of ovulation. Read more about it here and here.

It’s normal for this to occur occasionally. If it’s happening regularly, then you should talk to your doctor about PCOS. If that’s been ruled out, stress could be the cause. Stress disrupts the communication between your hypothalamus and anterior pituitary. The consequence of this disrupted communication is a mistiming of the release of pituitary hormones, and a subsequent lack of ovulation and/or estrogen and progesterone production by the ovaries.

If you are ovulating and your periods are still light, this could be normal for you. However, this could also be a sign of low estrogen levels due to smoking, under eating (a type of stressor) or too much soy or phytoestrogens in the diet.

I’ve kept this part of the discussion relatively brief because I covered anovulatory cycles thoroughly in this post.

Do you have prolonged bleeding?

Normal menstruation length is 3-7 days. If your flow lasts longer than seven days, you likely had an anovulatory cycle. That can occur with PCOS or perimenopause.

Polycystic ovary syndrome (PCOS)

The main symptom of PCOS is irregular periods – late periods or too many days of bleeding. Irregular periods are typically due to anovulatory cycles. In fact, PCOS is the most common cause of anovulation and ovulatory dysfunction in women (McCance KL & Huether SE, 2019).

The mechanisms of PCOS are better understood than the causes. According to medscape, the exact cause of this condition is unclear. “PCOS can result from abnormal function of the hypothalamic-pituitary-ovarian (HPO) axis. A key characteristic of PCOS is inappropriate gonadotropin secretion, which is more likely a result of, rather than a cause of, ovarian dysfunction” (Richard Scott Lucidi et al., 2019).

Key point: result of, rather than a cause of, ovarian dysfunction. But why is there ovarian dysfunction in PCOS?

PCOS is associated with elevated insulin levels (called hyperinsulinemia), which may have gonadotropin-augmenting effects on ovarian function. The main gonadotropins are follicle stimulating hormone (FSH) and luteinizing hormone (LH). These hormones are made and secreted by the anterior pituitary. They act upon the ovaries, where they regulate the production of steroid hormones. In PCOS, there is increased circulating LH and decreased FSH. This imbalanced LH:FSH ratio leads to excessive production of androgens:

“Under the increased stimulatory effect of luteinizing hormone (LH) secreted by the anterior pituitary, stimulation of the ovarian theca cells is increased. These cells, in turn, increase the production of androgens (eg, testosterone, androstenedione)” (Richard Scott Lucidi et al., 2019). This is why we see high androgens on a blood test or physical signs of androgen excess in people with PCOS.

High androgen levels in the ovary inhibit FSH; hence, they also inhibit development and maturation of the follicles. Ovarian follicles are sacs within your ovaries that contain the eggs. In a normal menstrual cycle, ovulation occurs when one dominant follicle (rarely two) finally ruptures and releases an egg. After ovulation, the emptied follicle restructures itself into a progesterone-secreting gland called the corpus luteum. Since there isn’t total suppression of FSH in PCOS, follicular growth continues. But not to the point of maturation, which is needed for ovulation. Increased androgen secretion by the ovaries contributes to premature follicular failure (known as atresia) and persistent anovulation. A vicious cycle ensues when the chronic absence of progesterone (due to anovulation) contributes to the high levels of LH and low levels of FSH. Over time, persistent anovulation causes enlarged polycystic ovaries characterized by a smooth, pearly white capsule.

The classic polycystic ovary that results from a state of chronic anovulation can be seen in the picture below:

Ultrasound of polycystic ovary

Source: McCance, K. L., & Huether, S. E. (2018). Pathophysiology: The biologic basis for disease in adults and children (8th ed.). St. Louis, Missouri. Elsevier Health Sciences. 1720 pages.

It’s much more complicated than this, with many other hormones and signalling pathways involved, but this provides a basic understanding of the hormonal mechanisms that lead to anovulation.

Diagnostic criteria for PCOS can get very confusing. Since PCOS is a syndrome (a group of symptoms) and not a disease per se, there is a broad set of criteria used to determine if a woman has PCOS. Different societies have different criteria. In my practice, I look at ovarian dysfunction (irregular periods) and signs of androgen excess (high androgens on a blood test or symptoms of high androgens such as hirsutism, acne, and androgenic alopecia).

This is similar to the criteria set forth by the Society of Obstetricians and Gynaecologists of Canada (SOGC). They indicate that a diagnosis of polycystic ovarian syndrome (PCOS) is made in the presence of at least 2 of the following 3 criteria, when other reasons for high androgens have been ruled out (eg. congenital adrenal hyperplasia, androgen-secreting tumors, or Cushing syndrome):

  1. Oligo-ovulation or anovulation*
  2. Clinical/biochemical evidence of hyperandrogenism
  3. Polycystic ovaries on ultrasonograms (Richard Scott Lucidi et al., 2019)

*Oligo-ovulation and anovulation manifested as infrequent or irregular periods and absence of periods, respectively.

Women with PCOS experience abnormal menstruation patterns due to infrequent, irregular or chronic anovulation. In general, the majority of abnormal uterine bleeding is due to lack of ovulation. Remember that ovulation is needed for progesterone, and progesterone keeps estrogen in check. Estrogen encourages endometrial growth, whereas progesterone limits growth. Without ovulation, menstrual flow may become irregular, excessive, or both, resulting from the large quantity of tissue available for bleeding (McCance KL & Huether SE, 2019). Treatment goals for women who experience irregularities in their menstrual bleeding due to lack of regular ovulation should focus on inducing regular menstrual cycles.


The first step in assessing abnormal bleeding is to determine the cause of bleeding. If no cause can be found, it is usually assumed that the bleeding is caused by lack of regular ovulation.

Abnormal uterine bleeding encompasses several patterns. In this post we covered the patterns that are observed during menstruation and what they might mean. In another post, I’ll cover the non-menstrual patterns of abnormal uterine bleeding, like mid-cycle bleeding, premenstrual bleeding, and bleeding after sex.

McCance, K. L., & Huether, S. E. (2018). Pathophysiology: The biologic basis for disease in adults and children (8th ed.). St. Louis, Missouri. Elsevier Health Sciences. 1720 pages.