Anemia and Periods

Periods affect many women in many different ways. Some may notice no uncomfortable side effects at all, while others might find this time of their cycle quite debilitating. Fatigue and dizziness are two symptoms that many women may dismiss as a ‘normal’ part of their period, but in fact, they may be a sign of something more.

Heavy or prolonged periods can deplete your iron stores and affect your red blood cell production, leading to anemia and triggering these feelings of tiredness and poor concentration.

But why? What causes this? And can it be prevented? We aim to answer all of this in this article as we unpack a condition that impacts more women than you may think.

Understanding Anemia and Periods

Anemia is a condition defined by low levels of hemoglobin*, and/or a low red blood cell count. This can lessen the amount of oxygen delivered throughout the body, leading to feelings of fatigue, dizziness, and weakness. 

There are many different types of anemia, with iron-deficiency anemia being among the most prevalent. Often caused by insufficient iron intake or blood loss, it’s particularly common among menstruating women, who on average lose roughly 30-40ml of blood during their period.

*Hemoglobin is a protein containing iron inside red blood cells, where it transports oxygen through your body. Women of reproductive age are at higher risk of low hemoglobin levels as monthly period blood loss depletes iron levels, which is essential for hemoglobin production.

What Causes Anemia in Women?

Most women of reproductive age will have a menstrual cycle, but having a period doesn’t necessarily mean you’re guaranteed to have anemia. So what causes this?

Some common factors that may be at play include:

• Heavy menstrual bleeding (also known as menorrhagia)

• Pregnancy/postpartum iron demand

• Poor dietary iron intake or absorption

• Chronic diseases, genetic, or bone marrow disorders

Balanced hormones are also a major part of the picture. Estrogen and progesterone work together to support overall well-being, and when they’re in sync, they can influence the intensity of your menstrual flow, sometimes even reducing hormone‑related heavy bleeding.

For women aged 15-49, heavy periods are the top cause of iron-deficiency anemia. If this sounds familiar, and you’d like more tailored guidance, our hormone health specialists offer personalized insights to help you understand what your body needs.

Can Anemia Affect Your Period?

The tricky thing about iron-deficiency anemia and periods is that they often influence each other in a loop. Low iron period blood loss due to heavy periods can cause anemia, which can go on to disrupt your hormones, in turn affecting the timing and flow of your cycle.

Anemia can also bring about its own uncomfortable symptoms and potentially dysregulate your cycle due to hormonal imbalances and poor oxygenation. When iron levels drop low enough to interfere with ovulation, it can lead to skipped cycles or, over time, even heavier periods.

Tracking your periods and understanding what’s normal for your body and what’s not is helpful for all women, but even more so if you think you may be anemic.

The Mira Hormone Monitor, along with the Mira App and Mira Wands, can help you spot any unusual changes in your cycle’s patterns and reveal potential causes that might correlate with being anemic and periods being heavier than they ought to be. This test measures LH, E3G, PdG, and FSH and uses AI trained on over 15 million hormone data points and one million menstrual cycles. It can detect subtle hormonal shifts over time and generate exportable trend reports that make discussions with a healthcare provider clearer and more informed.

How Heavy Periods Can Cause Anemia

Even if you’re not anemic to begin with, heavy periods can, over time, lead to consistent iron loss and increase your chances of developing menstrual anemia, leading to the telltale symptoms of fatigue, weakness, and dizziness.

Flow levels can vary for every woman and can even change from cycle to cycle, or as we age. But what counts as a ‘heavy’ period?

What Causes Heavy Periods

There are many factors that can impact the flow of our periods, whether it be certain medications or health conditions.

Some medical conditions include:

• Hormone imbalances (estrogen/progesterone)

• Uterine fibroids or polyps

• Endometriosis

• Ovulation problems

• Adenomyosis

• IUDs

• Medications (anticoagulants, aspirin)

• Bleeding disorders

Identifying what’s causing your heavy periods is an important step toward getting the right treatment. Understanding the root cause not only makes your cycle easier to manage and brings the relief you might need, but it may also help prevent related health issues down the line, including iron‑deficiency anemia.

How to Tell If You Have Low Iron During Period

It might seem tricky to tell the difference between ‘normal’ menstrual side effects and period anemia symptoms. Practical self-awareness and medical testing are two key ways to take a step in the right direction.

Try tracking any symptoms you may notice, such as exhaustion, brain fog, or breathlessness during your period. Noting the heaviness of your flow and how often you need to change your sanitary protection alongside these symptoms can also help you tell the difference between a normal period and an ‘anemia period’.

More diagnostic steps include having a complete blood count (CBC) test, a ferritin test, or testing for your iron saturation, which we shall touch more on later in this article. These tests can provide a more definitive answer, particularly if you’ve already noticed some potential signs through period tracking.

Signs of Anemia During Period

Understanding the common symptoms of anemia to watch out for can help you know when to consider seeking professional advice. These are some signs:

• Feeling tired or weak during or after menstruation

• Headache

• Insomnia

• Fatigue

• Pale or yellowish skin

• Dizziness, fainting, or shortness of breath

• Rapid heartbeat

• Difficulty concentrating

• Cold hands and feet

In addition to the above, some period-specific warning signs include:

• Needing to change pads/tampons every 1-2 hours for several hours in a row

• Passing blood clots larger than a quarter

• Periods lasting more than 7 days

Diagnosis

Receiving a diagnosis may feel daunting, but it’s important not to fear seeking advice from a medical professional. By diagnosing what you may be experiencing, they can help you receive the support and treatment you may need to make your periods more comfortable and manageable.

Being prepared for what your doctor may want to discuss can help put your mind at ease if you’re still feeling anxious about booking an appointment.

Here’s what you may expect during your consultation:

• Asking about your medical and family history

• Complete a physical and pelvic exam

• A complete blood count (CBC) test - this measures your hemoglobin and red cell count

• Ferritin* and iron studies (if needed)

• For heavy periods, pelvic ultrasound or a hysteroscopy may be necessary to identify potential uterine causes.

*Ferritin is a protein that stores iron in your body. Testing for this protein can show how much iron you have in reserve.

You might also find the Panorama Lab Test helpful for keeping an eye on any hormone fluctuations linked to iron depletion. This painless blood test offers a clear snapshot of hormonal health by measuring key hormones, including AMH, TSH, free T4 (fT4), prolactin, free testosterone, total testosterone, SHBG, and albumin. And if you’re looking for more personalized guidance, Mira’s specialists can provide tailored insights to help you understand what your body needs.

Treatment

If your diagnosis shows that you have anemia from period blood loss, your healthcare provider will be able to offer the appropriate next steps for you. 

Depending on the severity of your anemia, you may be recommended certain steps or treatments:

Remember, treatment is highly individual once the cause is identified. If you suspect you may be experiencing anemia, always reach out to a medical professional for support.

Prevention

While women with periods, particularly heavy periods, are more at risk of developing anemia, there are some proactive steps you can take to minimize your risk and support your body’s iron needs. We gain most of our iron through food, so certain diet switches can make the world of difference. 

Some helpful steps include:

• Eat iron-rich foods (red meat, spinach, lentils, shellfish, quinoa)

• Combine with vitamin C-rich foods for absorption

• Limit coffee/tea during meals

• Separate calcium supplements from iron

• (Always consult your doctor before taking iron tablets to avoid side effects)

• Drink targeted teas, such as the Mira Fertility Tea, which is designed to support gentle hormone balance and relaxation

• Take high-quality prenatal vitamins, which offer iron and folate supplementation

• Try PCOS supplements for targeting hormonal regularity, which may reduce your heavy periods

When to See a Doctor

If you have any concerns or worries, your doctor is always there to support you and offer helpful medical advice and support. 

However, please seek medical advice if you notice any of the following red flags:

• Periods lasting longer than a week

• Soaking through period protection every 1-2 hours for several hours in a row

• Passing large blood clots

• Feeling faint or breathless

• Extreme fatigue that affects your daily life

Being proactive and seeking medical care as early as you can when you notice the above symptoms can help you receive the appropriate diagnosis and treatment your body needs promptly.

The Bottom Line

Heavy or prolonged periods can lead to iron-deficiency anemia, and anemia can, in turn, have a knock-on effect on your period, but both are treatable. Through early recognition, proactive diet switches, testing, and professional support, there’s no reason why your anemia period symptoms can’t become more manageable, or treated entirely.

We hope you found this article helpful. Always remember to seek support whenever you’re unsure or worried about something, to ensure you’re prioritizing your overall health and well-being.

Frequently Asked Questions

Can anemia cause light or no periods?

Yes, in some cases, iron‑deficiency anemia can disrupt the hormonal signals that regulate menstruation, which may lead to unusually light periods or even missed periods.

Why do I get iron deficiency anemia on period?

Iron deficiency during your period is usually caused by losing more iron through menstrual blood than your body can replace, especially if your flow is heavy.

How can I be anemic when I don't have periods?

You can still become anemic without having periods because iron deficiency isn’t only caused by menstrual blood loss. It can also come from other sources of blood loss, low dietary iron, or medical conditions that affect absorption.

Does anemia cause painful periods?

While current evidence shows that anemia itself doesn’t directly cause painful periods, it can worsen fatigue and overall menstrual discomfort. Heavy or prolonged periods, which can be more painful, are more likely to cause anemia in the first place.

Can iron deficiency cause periods to stop/be very late?

Yes, research shows that low iron can disrupt the hormonal signals that control ovulation, which can delay your period or stop it altogether.