Fibroids and Anemia: Low Iron From Heavy Periods

Quick Answer

Fibroids can cause iron-deficiency anemia by making periods heavier, so you lose more iron each month than your body can replace. A blood count and ferritin test can find it, and lasting relief usually means replacing the iron and also treating the bleeding.

Yes, fibroids can cause anemia. They don't do it directly. Fibroids can make periods heavier and longer, and every heavy period drains some of the iron your body needs to make red blood cells. Over months, your iron stores run low (iron deficiency). If they drop far enough, your body can't make enough healthy red blood cells, and that is iron-deficiency anemia. The fix has two parts: replace the iron, and treat the bleeding that is causing the loss.

How fibroids lead to low iron

The American College of Obstetricians and Gynecologists (ACOG) lists "anemia (from blood loss)" as a fibroid symptom, along with longer, more frequent or heavier periods. The chain is simple. Iron is a key part of hemoglobin, the protein in red blood cells that carries oxygen. When you lose more blood each month than your diet can replace, your body uses up its stored iron first. You can be iron deficient for a long time before a standard blood count shows anemia.

Heavy menstrual bleeding is common. A 2021 review of 22 international guidelines estimated that up to one in three women of reproductive age has heavy periods. The same review found that iron deficiency linked to heavy bleeding is "likely to be underdiagnosed and undertreated," partly because many guidelines check for anemia but not for low iron stores.

Fibroid location matters less than you might expect. In a 2011 study of 357 women seeking fibroid embolization, women were equally likely to report heavy bleeding or to have been diagnosed with anemia regardless of where their fibroids were. A 2024 analysis of US insurance claims for women with fibroids and heavy bleeding found anemia was coded more often in Black women than in White women, in both commercial and Medicaid plans. Because claims only capture anemia that someone diagnosed and billed, the true rates are likely higher.

Signs your iron may be low

According to the National Heart, Lung, and Blood Institute (NHLBI), mild or moderate iron-deficiency anemia may cause no symptoms at all. When symptoms appear, they often creep up so slowly that you may blame them on stress, poor sleep or a busy life. Common signs include:

Tiredness that does not improve with rest
Dizziness or lightheadedness, especially when you stand up
Pale skin
Cold hands and feet
Shortness of breath with activity you used to manage easily

The NHLBI also notes that untreated iron-deficiency anemia can lead to complications such as restless legs syndrome. If you have heavy periods and any of these symptoms, ask for a blood test rather than waiting for them to pass.

The blood tests that find it

Testing is straightforward. The NHLBI describes a blood test that checks your complete blood count (CBC), hemoglobin, blood iron and ferritin. Ferritin reflects how much iron your body has stored.

Complete blood count. The UK's NICE guideline on heavy menstrual bleeding (NG88) recommends a full blood count for every woman with heavy periods. It shows whether you are anemic now.
Ferritin. This can show low iron stores even when your hemoglobin is still normal. In 2026 the American Society of Hematology published new guidelines for diagnosing iron deficiency. They include ferritin thresholds for specific groups, aimed at catching iron deficiency "irrespective of the presence of anemia." Your doctor will read your result against the cutoff that fits you.

If you have already been told you are anemic, bring copies of your recent blood work to any fibroid consultation. It helps your doctor judge how urgent treatment is and which options fit.

Questions about your treatment options? Dr. Fox can help.

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This article is part of our Fibroid Treatment Guide.

Replacing the iron

Iron replacement treats the result, not the cause. According to the NHLBI:

Oral iron (iron pills) is the most common treatment. Rebuilding your iron often takes three to six months.
Intravenous (IV) iron is given through a vein, often in one or a few sessions. It is more likely to be used for serious cases or when pills are not enough.
Blood transfusion is reserved for serious cases.

The 2021 guideline review found that oral iron was generally recommended first. Some guidelines recommended IV iron for severe anemia, for people who do not respond to pills, or before surgery. Iron pills alone are not the whole answer, because your doctor also needs to find and treat the reason your iron is low.

Fixing the cause: treating the bleeding

If heavy periods continue, iron pills are like bailing water from a boat with a leak. The NHLBI notes that iron-deficiency anemia may be preventable when the cause of blood loss is treated. For fibroid-related bleeding, ACOG's 2021 practice bulletin describes a range of choices.

Option	What it does	Worth knowing
Tranexamic acid	Non-hormonal pills taken during your period to reduce bleeding	ACOG says it "can be considered"; does not shrink fibroids
Hormonal IUD (52-mg levonorgestrel)	A small device placed in the uterus that releases a hormone to reduce bleeding	ACOG says it "can be considered"
Oral GnRH antagonist with add-back hormones	Daily hormone-lowering pills combined with low-dose add-back hormones	ACOG supports use for up to 2 years because of bone-loss concerns
Myomectomy	Surgery that removes fibroids and keeps the uterus	Fibroids can come back
Uterine fibroid embolization (UFE)	Blocks the blood supply to the fibroids so they shrink	Keeps the uterus; no abdominal incision
Hysterectomy	Removes the uterus	Ends periods for good; major surgery

Medicines can control bleeding for many women and are often tried first. Our guide to fibroid medications explains each one. When bleeding does not respond, or you would rather not take medicine long term, a procedure may make more sense.

Uterine artery embolization is one of those procedures. ACOG recommends it for patients who want to keep their uterus, with counseling about the limited data on pregnancy afterward. A few points from the research are relevant to anemia:

In the US FIBROID Registry (more than 2,000 patients), heavy bleeding as the main symptom was one of the factors that predicted greater improvement after embolization.
A 2014 Cochrane review of 7 randomized trials (793 women) found blood transfusion was less likely with embolization than with surgery.
The same review found more women needed a further procedure within 2 years after embolization than after surgery.
Results take time. ACOG's patient guide says it may take 2 to 3 months to see a change in symptoms, so iron replacement usually continues during that period.

If you want to keep your uterus or have future pregnancy plans, see how UFE compares with myomectomy. For a full overview of the procedure, read our page on uterine fibroid embolization (UFE). To see every option side by side, start with our fibroid treatment guide.

When to get help quickly

Low iron usually builds slowly, but some situations should not wait for a routine appointment. Get medical care promptly if you have:

Chest pain or shortness of breath. The NHLBI lists both as symptoms of more serious iron-deficiency anemia.
Fainting, or dizziness so strong you cannot stand safely
Bleeding so heavy that you feel faint or unwell
Any bleeding after menopause, which always needs prompt evaluation

For more on what counts as heavy, read heavy periods and fibroids. If you are still sorting out whether fibroids explain how you feel, our overview of fibroid symptoms is a good next step.

Questions to bring to your appointment

What are my hemoglobin and ferritin levels, and how low are they for me?
Should I take iron by mouth, or would IV iron help me recover faster?
How long should I keep taking iron, and when will you recheck my blood?
Are my fibroids the likely cause of my bleeding, or do I need other tests?
Which treatments would stop the bleeding while fitting my plans for pregnancy and my wish to keep, or not keep, my uterus?

Anemia from fibroids is common and treatable. Replacing iron helps you feel better now. Treating the bleeding keeps the problem from coming back.

Frequently Asked Questions

Can fibroids cause anemia?

Yes. Fibroids can make periods heavier or longer, and the extra blood loss can use up your iron stores. ACOG lists anemia from blood loss as one of the symptoms of fibroids.

Can I be low in iron even if my blood count is normal?

Yes. Iron stores usually fall before anemia shows up on a blood count. A ferritin test can show low stored iron, and 2026 American Society of Hematology guidelines focus on diagnosing iron deficiency whether or not anemia is present.

How long does it take to fix iron-deficiency anemia?

According to the NHLBI, restoring iron with pills often takes three to six months. IV iron can be given in one or a few sessions. If heavy bleeding continues, the anemia can return, so the cause also needs treatment.

Will treating my fibroids fix my anemia?

Treating the bleeding removes the main reason iron keeps running low. Many women still need iron replacement for a time while their levels recover, and some treatments, such as embolization, can take 2 to 3 months to change symptoms.

When is anemia from heavy periods an emergency?

Get prompt care for chest pain, shortness of breath, fainting, or bleeding so heavy that you feel faint or unwell. Any bleeding after menopause should also be checked promptly.

Keep Reading

Sources

Medically reviewed by David Fox, MD, FACS, RPVI. This article is general information, not a substitute for a medical evaluation.

Living with heavy periods, pelvic pressure or other fibroid symptoms? Schedule a consultation with Dr. David Fox at Fox Vein & Vascular in Manhattan to find out whether uterine fibroid embolization is right for you. Call (212) 362-3470 or request a UFE consultation online.

Fibroids and Anemia: Why Heavy Periods Drain Your Iron