Anemia, Iron & Blood Health
Iron Deficiency Anemia in Women: Symptoms, Causes and Treatment
Iron deficiency anemia means your body doesn't have enough iron to make healthy red blood cells, so less oxygen gets to your tissues. In women it's most often caused by heavy periods, pregnancy or not absorbing enough iron. It's diagnosed with simple blood tests and is very treatable once the cause is found.
The tricky part is that it creeps up. Many women don't realize how tired they were until they're treated and suddenly can climb the subway stairs without stopping halfway.
Does this sound like you?
Symptoms come on slowly, so it's easy to blame work, kids or getting older. Common ones:
- Tiredness that doesn't get better with sleep
- Getting winded or feeling your heart pound on stairs or a short walk
- Pale skin, or pale inner eyelids
- Headaches, dizziness or lightheadedness when you stand up
- Cold hands and feet, even when others are comfortable
- Brittle or spoon-shaped nails
- More hair in the shower drain
- Restless legs, especially at night
- Cravings for ice, clay, starch or other non-food things (called pica)
That last one surprises people, and it's more common than you'd think. If you find yourself crunching through cups of ice every day, mention it. It's a classic clue, and no one will think it's strange.
Some women have no clear symptoms at all, and anemia shows up on a routine blood test.
Iron deficiency vs. iron deficiency anemia
Hemoglobin is the protein in red blood cells that carries oxygen, and it needs iron. When iron runs low, your body uses up its stores first. If the shortage keeps going, it can't make enough hemoglobin, and anemia develops.
- Iron deficiency without anemia: stores are low, but hemoglobin is still normal. You can still feel tired.
- Iron deficiency anemia: stores are depleted and hemoglobin has dropped below normal.
The World Health Organization defines anemia in non-pregnant adult women as hemoglobin below 12 g/dL. Pregnancy uses different cutoffs, which your prenatal team will apply.
What causes it in women?
Heavy periods. The most common cause if you menstruate. You lose more blood each month than your diet can replace, and your iron slowly drains. Many women don't know their periods are heavy, because they've always been that way. The CDC's signs of heavy bleeding:
- Soaking through a pad or tampon every hour for several hours in a row
- Needing to change protection overnight
- Periods lasting longer than 7 days
- Passing clots the size of a quarter or larger
More in heavy periods and anemia.
Pregnancy and childbirth. A growing baby and placenta need a lot of iron, and blood volume rises. Blood loss at delivery can leave you low afterward, right when you're also short on sleep.
Not absorbing enough iron:
- Celiac disease or inflammatory bowel disease
- Weight-loss (bariatric) surgery
- Long-term use of acid-reducing medicines
- Diets low in iron, including some vegetarian or vegan diets without careful planning
Other blood loss. Bleeding from the stomach or intestines (from ulcers, frequent anti-inflammatory pain relievers or polyps, for example) can cause it. Iron deficiency in someone who no longer has periods always deserves a look for a bleeding source.
The blood tests, and what they mean
| Test | What it shows |
|---|---|
| Complete blood count (CBC) | Hemoglobin and red cell size; iron deficiency often makes cells small |
| Ferritin | Your iron stores; low ferritin is the most specific sign of iron deficiency |
| Iron, TIBC and transferrin saturation | How much iron is circulating and available |
| Reticulocyte count | Whether your bone marrow is making new red cells |
Here's the part worth knowing before you look at your portal. In 2026 the American Society of Hematology (ASH) issued guidelines suggesting a ferritin of 30 ng/mL or lower to diagnose iron deficiency in menstruating and pregnant people, higher than the older cutoff of 15 that many labs still flag. So a ferritin of 22 might show up as "normal" on your report and still mean you're iron deficient. If your number is under 30, ask about it. See what low ferritin means.
Your clinician may also look for the cause: detailed questions about your periods, a celiac test, or a stool test or GI evaluation.
Treatment: two jobs
Treatment has to do two things: put the iron back, and fix the reason it was lost. Skip the second one and anemia usually comes back.
Iron pills
Pills are the usual first step. They're cheap and work well for many people. The common complaints are constipation, nausea and an upset stomach, and plenty of people quit because of them without telling anyone. Don't. Call your clinician instead, because there are often other options. Your clinician will tell you which product to take, how much and how often. Don't change the dose on your own.
Expect to feel better gradually. Hemoglobin often starts rising within a few weeks, but refilling your stores takes a few months, and your clinician will recheck your blood.
IV iron
Intravenous (IV) iron goes straight into a vein. Clinicians may recommend it when:
- Pills cause side effects you can't tolerate
- Your levels don't improve on pills
- Something blocks absorption, such as bariatric surgery
- You need iron replaced quickly, like later in pregnancy or before surgery
- Ongoing heavy bleeding outpaces what pills can replace
An infusion is usually done at an infusion center or clinic while you sit in a recliner, and depending on the product it takes anywhere from about 15 minutes to a few hours. Your clinician can explain which option fits you.
Fixing the cause
If heavy periods are the reason, a gynecologist can talk through hormonal treatments, non-hormonal medicines or procedures, and may check for fibroids, polyps or a bleeding disorder.
Food
Iron-rich foods help keep levels up but usually can't correct anemia on their own. Good sources: red meat, poultry, fish, beans, lentils, tofu and fortified cereals. Vitamin C helps you absorb iron from plant foods. Tea, coffee and calcium can reduce absorption when taken with iron-rich meals, so move your coffee an hour or so away from your iron-rich lunch.
When to see a doctor
Make an appointment if you:
- Feel tired, short of breath or dizzy most days
- Have periods that are heavy, long or include large clots
- Are pregnant or planning pregnancy and feel run down
- Have been told you're anemic but don't know why
- Have taken iron for a few months without feeling better
Get urgent care for chest pain, fainting, a racing heartbeat at rest, severe shortness of breath, or black or bloody stools.
An OB/GYN, gynecologist or women's health nurse practitioner is a good place to start, especially when periods are the likely cause. You can search for a provider near you and filter by borough or county.
Seeing a hematologist in New York
A hematologist is a blood specialist. Your OB/GYN or primary care clinician may refer you if your anemia is severe, doesn't respond to pills, keeps coming back, or if you might need IV iron. Hematologists also check for bleeding disorders like von Willebrand disease, which can be a hidden cause of heavy periods.
In the New York area, hematology care is offered through hospital systems and community practices. Premier Hematology & Oncology, which sponsors our professional resources, provides hematology consults and IV iron infusions at centers across NYC, Long Island and the Hudson Valley. Clinicians can learn more on our hematology partners page.
Frequently asked questions
What are the first signs of iron deficiency anemia in women?
Common early signs are tiredness that doesn't improve with rest, getting winded with activity, pale skin, headaches and feeling cold. Some people also crave ice or other non-food items.
What is the most common cause of anemia in women?
Iron deficiency is the most common cause of anemia worldwide, and in women of reproductive age it's most often linked to heavy menstrual bleeding or pregnancy.
How long does it take to fix iron deficiency anemia?
With treatment, hemoglobin often starts rising within a few weeks, but rebuilding iron stores usually takes a few months. Your clinician will recheck your blood to confirm you're recovering.
Should I take an iron supplement on my own?
Get tested first. Iron supplements can cause side effects and can hide the cause of blood loss, so ask your clinician whether you need iron and how much to take.
Sources
- WHO — Guideline on haemoglobin cutoffs to define anaemia in individuals and populations (2024)
- American Society of Hematology — Guidelines for the Diagnosis of Iron Deficiency (2026)
- NHLBI — Iron-Deficiency Anemia
- NIH Office of Dietary Supplements — Iron Fact Sheet for Consumers
- CDC — Heavy Menstrual Bleeding
This article is for general education and is not medical advice. It does not replace an evaluation by a licensed clinician who knows your history. If you think you have a medical emergency, call 911.