Iron Deficiency Hits 30 Million U.S. Women, Driving Fatigue and Brain Fog

Q: Standard blood tests often miss it. What is the one crucial number you must ask your doctor about?

Ask your doctor for your **ferritin level**. Ferritin is the blood marker that shows how much iron your body has in storage. That matters because many standard tests, especially a routine complete blood count, mainly look for anemia by checking hemoglobin. You can have iron deficiency, with fatigue, brain fog, poor concentration, hair thinning, or restless legs, even when hemoglobin is still normal. Experts cited in the reporting say this is why iron deficiency is often missed, particularly in menstruating women and during pregnancy. A fuller workup usually includes ferritin, iron saturation, and a CBC, but ferritin is the key number to ask about because it can reveal depleted iron stores before anemia appears. A ferritin level **below about 30 ng/mL (mcg/L)** is widely considered a strong sign of iron deficiency, though some clinicians use higher cutoffs in certain situations. One important caveat is that ferritin can look falsely normal or high during inflammation or illness, so doctors may interpret it alongside other iron studies. If symptoms fit and ferritin is low, treatment may include oral iron or IV iron, while also looking for the cause, such as heavy periods, pregnancy-related needs, or gastrointestinal blood loss.

2 articles · Updated · HuffPost · Jun 14

About 30 million U.S. women have iron deficiency, experts said, with roughly 15% experiencing iron deficiency anemia and another 15% to 20% low iron without anemia.
Fatigue is the most common symptom, but low iron can also impair concentration, memory and mood, and trigger shortness of breath, dizziness, ice cravings, restless legs and hair thinning.
Menstrual blood loss is the main driver in premenopausal women, though heavy periods often go unrecognized; pregnancy, gastric bypass surgery, inflammatory bowel disease and gastrointestinal disorders can also be causes.
U.S. doctors do not routinely screen for iron deficiency, experts said, leaving many cases undiagnosed even though blood tests can detect it and treatment with oral or IV iron can improve quality of life.
Pregnancy raises the stakes because low iron is linked to preterm birth, low birth weight and developmental delays, with experts saying the burden falls disproportionately on Black pregnant patients.