Heavy periods can cause major blood loss and, in turn, iron loss. Your body needs iron to make hemoglobin, the protein that helps your red blood cells carry oxygen throughout your body.
About 30% of people with heavy periods have low iron, and 60% develop iron deficiency anemia if the blood loss continues.
If you think you have anemia, your healthcare provider can help by suggesting iron-rich foods, recommending supplements, or prescribing hormonal or nonhormonal medications.
Heavy periods can cause anemia by making you lose too much blood and iron.
This can happen when your body:
- Breaks down red blood cells (RBCs) too quickly, which can occur due to having an autoimmune disease or heart valve problem
- Doesn’t absorb iron well due to conditions like Crohn’s disease
- Doesn’t make enough RBCs, which can be due to vitamin deficiencies or kidney disease, among other factors
- Loses too many RBCs due to heavy bleeding
- Needs more iron than it’s getting due to factors like being pregnant or playing endurance sports
Menorrhagia (heavy periods) are a leading cause of iron deficiency anemia, potentially responsible for up to 41% of cases in reproductive-aged people assigned female at birth.
How Much Blood Is Lost Normally?
Most people lose about 2-3 tablespoons (30–40 milliliters) of blood during their period. If you have heavy menstrual bleeding, you may lose more than 5 tablespoons (80-plus milliliters) per period. People with heavy menstrual bleeding also lose more iron, which can eventually lead to iron deficiency anemia, the most common type of anemia.
You may have a heavy period that can put you at risk of anemia if you:
- Bleed between periods
- Bleed for more than seven days
- Change pads or tampons every hour or more
- Pass blood clots larger than a quarter
- Skip out on daily activities or social events due to period difficulties
- Use multiple forms of protection to manage the flow
- Wake up at night to change pads or tampons
Risk Factors for Anemia Due to Heavy Periods
Potential causes of heavy periods include:
- Age: Puberty (teen years) and people in their 40s experiencing perimenopause (the time leading to menopause)
- Blood disorders: Examples include von Willebrand disease, platelet disorders, leukemia (blood cancer), and clotting factor deficiencies
- Chronic illnesses: These include conditions such as kidney disease or thyroid disorders
- Copper intrauterine device (IUD): This is a small, T-shaped copper birth control device inserted into the uterus to prevent pregnancy
- Hormone imbalances: Common causes include puberty, perimenopause, and polycystic ovary syndrome (PCOS), a condition that causes you to make too many androgens (male hormones)
- Lifestyle or environmental factors: These include frequent blood donations, restrictive diets, low body weight, stress, and intense exercise
- Medications: Examples include blood thinners like Coumadin (warfarin) or aspirin
- Uterine (womb) conditions: Examples include fibroids or polyps (noncancerous growths in the uterus), adenomyosis (the uterine lining grows into the muscle), endometriosis (tissue similar to the uterine lining grows outside the uterus), scar tissue, pelvic inflammatory disease (PID), and uterine cancer
Anemia can affect your menstrual cycle in several ways.
You may experience:
- Irregular periods
- Lighter or pinkish period blood flow; research is limited, but many females note this change
- Worsened PMS symptoms, like mood swings, headaches, and irritability
Anemia can also cause:
- Brain fog
- Brittle nails, skin, or hair
- Cold hands and feet
- Dizziness
- Easy bruising
- Tachycardia (fast or irregular heartbeat)
- Fatigue (extreme tiredness)
- Migraines
- Pale skin or nail beds
- Pica (craving non-food items like ice, dirt, or paper)
- Restless leg syndrome
- Shortness of breath, even after light activity
Your healthcare provider can check for anemia by asking about your health history, doing a physical exam, and ordering diagnostic tests.
Medical History and Physical Examination
Your provider will ask about symptoms and details about your period, diet, and medical history.
During a physical exam, they’ll check for signs of anemia like:
- Pallor (unusually pale skin) or pale inner eyelids
- Fast or irregular heartbeat
- Postural hypotension (low blood pressure when standing)
- Swelling or tenderness in your belly
- Nail or skin changes
They may also perform a pelvic exam to check for abnormalities in your uterus or ovaries that may cause heavy bleeding.
Diagnostic Tests for Anemia
Healthcare providers may order these blood tests if they suspect you have anemia:
- Coagulation tests: This checks the proteins in your blood that affect blood clotting, a function in the body that stops you from bleeding too much. Coagulation tests can help diagnose certain bleeding disorders.
- Complete blood count (CBC): This measures your red blood cells and hemoglobin levels. This test can determine if you have anemia, certain blood diseases, and infections.
- Ferritin serum test: This measures how much iron you have in your body. However, this test isn’t as accurate if you also have an inflammatory condition.
- Hormone panels: This checks for hormonal imbalances or thyroid disorders, which can affect hormones.
- Iron level test: Also known as the serum iron test, this measures the amount of circulating iron in the blood to see if your iron levels are too high or too low.
- Peripheral blood smear: This examines the shape and size of your red blood cells. Blood smears can help monitor and diagnose many conditions, including infections, blood and bone marrow disorders, and certain parasites.
- Reticulocyte count: This measures young red blood cells.
- Total iron-binding capacity (TIBC): This determines how well your blood moves iron through your body.
Your provider may also use imaging tests, like a pelvic ultrasound, which uses sound waves to create images of your uterus and find the cause of heavy bleeding.
In some cases, your provider may perform a hysteroscopy. During this minimally invasive procedure, they can examine the inside of your uterus by inserting a thin, flexible tube with a camera through your cervix and into your uterus.
Providers treat anemia by increasing iron levels and addressing the underlying cause of heavy bleeding. Treatment options include dietary changes, supplements, and medications. More serious cases may require surgery.
Iron-Rich Foods
Eating iron-rich foods can help prevent or treat anemia.
Iron-rich food sources include:
- Clams, oysters, shrimp, and sardines
- Dried fruits, including apricots and raisins
- Eggs
- Iron-fortified cereal, whole-wheat bread, oatmeal, and quinoa
- Leafy greens, such as spinach and kale
- Lentils, beans, and nuts
- Red meat or liver
- Tofu
Your body absorbs iron from lean meats, poultry, and eggs more easily than plant-based foods. For this reason, vegetarians often need to eat 1.8 times more iron than meat eaters. You can also help your body absorb iron better by eating vitamin C-rich foods like oranges, strawberries, and tomatoes.
If your diet doesn’t provide enough iron, your provider may recommend iron or multivitamin supplements. Always consult them before taking iron to avoid side effects like nausea or constipation.
Calcium-rich foods (such as dairy), coffee, and tea can interfere with iron absorption. It’s best to consume these separately and space them apart from iron-rich meals and supplements.
Medical Treatments for Heavy Periods
If heavy bleeding causes anemia, providers may recommend:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): Over-the-counter (OTC) options include Advil, Motrin (ibuprofen), and Aleve (naproxen).
- Hormonal birth control: This includes pills, patches, intrauterine devices (IUDs), vaginal rings, or shots that help regulate bleeding.
- Selective progesterone receptor modulators (SPRMs): These are medications that can help shrink fibroids.
- Gonadotropin-releasing hormone (GnRH) treatments: This lowers hormone levels to reduce heavy bleeding before surgery or for people with fibroids.
- Blood transfusions: Transfusions are generally reserved for more severe cases or those at high risk for complications.
- Iron infusions: This is done for severe anemia or before surgery. Newer formulations have reduced the risk of side effects.
Severe cases may require surgical treatments like:
- Endometrial ablation: This removes the uterine lining
- Myomectomy: This removes fibroids without removing the uterus
- Uterine artery embolization: This helps shrink fibroids
- Hysterectomy: This removes the uterus; done in serious cases
Prevention Strategies
To prevent anemia from heavy periods, consider these steps:
- Discuss birth control options with your provider
- Eat a diet rich in vitamins B and C, folate, protein, and iron
- Track your period to monitor flow, length, and clot size
- Talk to your provider about nonhormonal medications like Motrin, Advil (ibuprofen), Lysteda (tranexamic acid), or Ponstel (mefenamic acid) to reduce cramping and bleeding
Heavy periods can cause anemia, a condition where your blood does not transport enough oxygen to your tissues and organs. It can lead to symptoms like fatigue, dizziness, and weakness.
Eating iron-rich foods, taking supplements, and treating heavy period bleeding with medications or procedures can help.
If you have symptoms, talk to your provider to get an accurate diagnosis and prevent complications.