condition-guides

Iron Deficiency Anemia and Heavy Periods

Heavy periods are the most common cause of iron deficiency anemia in premenopausal people. Learn what to track and when to get tested.

What Heavy Periods Do to Your Iron Levels Every menstrual cycle uses up iron. The body replaces it through food, but there is a limit to how much the gut can absorb each day. When menstrual blood loss consistently exceeds what the body can replace, iron stores drop. Ferritin (stored iron) falls first. Then, once reserves run out, hemoglobin drops and anemia sets in. This happens slowly. Heavy periods do not cause sudden anemia. They cause a gradual decline that people adapt to. You get used to feeling tired. You blame breathlessness on being out of shape. You assume lightheadedness when standing is normal. By the time many people are diagnosed, their ferritin is very low. Tracking your bleeding is an early warning system that blood tests alone can miss. Blood tests only happen when someone orders them. This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. What to Track Flow volume with specifics. "Heavy" is vague. Track product type, changes per day, and saturation level. Note whether you double up (pad plus tampon), use overnight products during the day, or set alarms to change products overnight. These de