Iron Deficiency Anemia From Heavy Menstrual Periods

Getting Evaluated If You Are at Risk

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Iron deficiency anemia from heavy menstrual periods is very common. In women of childbearing age, it is the most frequent cause of iron deficiency anemia. Heavy menstrual bleeding is estimated to affect up to a third of premenopausal women, and some of these women are at risk of iron deficiency anemia, which can cause symptoms like fatigue.

In the U.S., around 4% of women of reproductive age have iron deficiency anemia. Black women in the U.S. and women in developing countries have even higher rates. The risk of iron deficiency anemia is one reason you should get yourself checked out if you have very heavy or prolonged menstrual periods.

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What Is Iron Deficiency Anemia?

Anemia is a medical condition in which you have a lower concentration of red blood cells in your blood than normal. It can have many different underlying causes, including genetic diseases, vitamin deficiencies, drug side effects, autoimmune diseases, and radiation and chemotherapy treatments.

Iron deficiency is one of the most common causes of anemia. Iron is an important component of hemoglobin, the part of your red blood cells that carries oxygen. So, if there isn’t enough iron around, your body can’t make enough healthy red blood cells.

If you don’t get enough iron in your diet, that can cause iron deficiency and anemia. Iron deficiency anemia might also be a problem if your body is having trouble absorbing iron for some reason.

But you can also get iron deficiency anemia if you lose blood gradually over a period of time. That’s why abnormally heavy periods can lead to iron deficiency anemia. That’s a problem because this condition can lead to fatigue, dizziness, reduced mental sharpness, and an overall decreased sense of well-being.

Heavy Menstrual Bleeding

Heavy menstrual bleeding refers to abnormally heavy or prolonged menstrual blood loss. (The medical term for this is “menorrhagia.”) Heavy menstrual bleeding can be accompanied by discomfort, low mood, decreased energy, and social embarrassment.

A heavy menstrual period is defined as one that lasts more than seven days, or one in which more than 80 milliliters (5.4 tablespoons or one-third of a cup) of blood is lost.

Practically speaking, it can be hard to get a sense of whether you have heavy menstrual bleeding. Some women may lose quite a bit of blood during their menstrual period but not realize it. Other women may perceive themselves to have heavy periods, but they may actually lose a normal range of blood each month.

Taking Notes to Share With Your Healthcare Provider

If you have concerns that you might have heavy menstrual bleeding, it may be helpful to take notes of how often you are needing to change your pads or tampons during your period. Also note the duration and frequency of your cycles. That way, you'll have up-to-date information to share with your healthcare provider.

Heavy menstrual bleeding is usually talked about in the context of a broader problem: abnormal uterine bleeding. This is a broader category that refers to medical issues that cause other unusual menstrual patterns as well, such as irregular, frequent, or absent periods, or bleeding after menopause.

Abnormal uterine bleeding can be caused by many different medical problems. Some of these include:

  • Disorders of ovulation (such as polycystic ovary syndrome)
  • Infection (such as in pelvic inflammatory disease)
  • Thyroid disorders
  • Kidney disease
  • Endometriosis
  • Uterine fibroids, polyps, or cancer
  • Inherited genetic disorders of blood coagulation
  • Drug side effects (such as from some antipsychotic drugs)
  • Hormonal contraceptive side effect
  • Copper-based intrauterine contraceptive device side effect (like Paragard)

Some people also seem to have heavy menstrual periods due to subtle dysfunction of the endometrial lining of the uterus, although this is not well understood. Some of these issues can lead to prolonged, frequent, or heavy bleeding that can lead to iron deficiency over time.

When Menstrual Bleeding Is an Emergency

Heavy menstrual bleeding can sometimes be a medical emergency. If you experience sudden, extremely heavy bleeding, seek urgent medical care. People who are pregnant should also check in with their clinician if they experience bleeding of any kind.


It’s important to seek medical evaluation if you believe you might have heavy menstrual bleeding. You might have an underlying medical issue that needs to be addressed.

Heavy menstrual bleeding or other kinds of abnormal uterine bleeding can also be uncomfortable and inconvenient. Moreover, you might have developed iron deficiency and iron deficiency anemia, which should be treated.

Sometimes an individual is checked for iron deficiency anemia because they are reporting heavy menstrual bleeding or other abnormal bleeding. Other times, a person might need to be checked for gynecological causes if they are found to have iron deficiency anemia.

In other cases, iron deficiency might be picked up when investigating another health problem, and the underlying cause needs to be discovered.

Anemia Diagnosis

Diagnosis of the anemia itself is relatively straightforward. A simple blood test called a complete blood count (CBC) provides information about the concentration of hemoglobin in your blood as well as the size of the red blood cells.

In non-pregnant women, anemia is defined as a hemoglobin concentration of 12 grams per deciliter (g/dl) or below. In people with anemia from iron deficiency, the red blood cells are also usually smaller than normal.

The CBC may be the only test needed to diagnose iron deficiency anemia. Other times, people need additional tests related to iron, such as serum ferritin.

Sometimes, a person might have iron deficiency anemia from heavy menstrual blood loss but also from another factor, like poor dietary iron intake or poor absorption of iron from a medical problem. In these cases, further assessment might be necessary,

The diagnostic approach to finding the underlying cause of iron deficiency anemia is somewhat different in women who have gone through menopause and in men. These individuals have a much higher chance of having a serious underlying condition causing iron deficiency anemia (like different types of cancer).

Abnormal Uterine Bleeding Diagnosis

It is also sometimes helpful to diagnose the underlying cause of heavy menstrual bleeding. Unfortunately, finding a correct diagnosis sometimes takes a while, and an underlying cause isn’t always identified.

Diagnosis includes your medical history, especially your gynecological history. You’ll want to tell your clinician as much as possible about the nature of your menstrual periods. If there has been a recent change, or any new symptoms, like fever, you should note that as well.

Make sure to tell your clinician about all medications you are taking. Include any over-the-counter medications and any birth control or hormone therapies.

The medical exam is often important as well. Typically, this will include a pelvic exam and possibly an ultrasound.

Depending on the context, one might need certain blood tests. For example, a thyroid-stimulating hormone (TSH) test might be used to see if a thyroid problem might be part of the issue, and a pregnancy test is usually needed as well.

Other blood tests might be needed in particular circumstances, like tests for blood coagulation disorders, or tests for certain hormones.

Imaging tests might include:

  • Pelvic ultrasound
  • Hysterosonography (ultrasound that visualizes inside the uterus)
  • Hysteroscopy (used to examine inside the uterus and sometimes obtain sample)
  • Magnetic resonance imaging (not usually needed)


Treatment focuses on addressing the source of the heavy menstrual bleeding. Certain causes have very specific treatments, like thyroid hormone for thyroid disease, or a treatment called desmopressin for people with bleeding disorders.


For heavy menstrual bleeding without a clear cause, hormone treatments are a mainstay treatment. For example, many women have improved symptoms with use of an intrauterine device that releases the hormone levonorgestrel (such as Mirena).

Oral contraceptive pills are also often helpful. These may be the type that contain both estrogens and progestins or the type containing progestins only. Both types can help regulate your cycle so that bleeding isn’t quite so heavy or prolonged during your period.

Another medication sometimes used is tranexamic acid (Lysteda), which makes your blood clot more easily. This might be a good option if you are considering trying to become pregnant soon. Over-the-counter medications, such as ibuprofen, can also help lessen the symptoms of discomfort that come with very heavy periods.

Surgeries and Procedures

If a specific structural source of the heavy menstrual periods is found, other treatment options may make sense. For example, someone with endometrial polyps might have reduced symptoms if they have them removed via hysteroscopic surgery that can be performed at your healthcare provider’s office.

A similar procedure, endometrial ablation, may also be a possibility for some individuals. Hysterectomy—complete removal of the uterus—is often highly effective. However, these last two are not an option for people who would like to have more children.

Diet and Supplements

Your clinician may suggest that you eat foods high in iron, such as spinach and meat. You may also need to take iron supplements while your body builds back its store of functioning red blood cells.

Taking iron can cause side effects like stomach discomfort, nausea, and constipation, but some of these can be reduced by taking the iron with meals. If for some reason you can’t take iron orally, you might need to get an iron infusion through an intravenous line.

In either case, this should take care of your iron deficiency anemia gradually. If your iron deficiency is very severe, you might need a blood transfusion, but this isn't usually necessary. After treatment, you may need repeat blood tests to make sure your iron deficiency anemia has indeed resolved.

A Word From Verywell

Many people don't realize that their heavy menstrual periods put them at risk of anemia from iron deficiency. It's worth getting checked out if you think this may be an issue for you. Don't hesitate to bring it up with your clinician. Fortunately, multiple different treatment options may help you get your heavy periods under control and reduce problems from this potential complication.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Ruth Jessen Hickman, MD
Ruth Jessen Hickman, MD, is a freelance medical and health writer and published book author.