In this episode, we will cover a complete overview of definition, diagnosis, treatment and monitoring of iron deficiency anemia (IDA). Key Concepts Iron-deficiency anemia (IDA) is the most common type of nutritional anemia. The most common risk factors are insufficient dietary intake, malabsorption, and increased requirement states like pregnancy or blood loss. Serum ferritin serves as the most confirmatory lab test for diagnosis of IDA. A low serum ferritin level usually indicates the presence of IDA. Other iron studies and CBC can be helpful in diagnosing IDA as well.  Generally oral iron therapy is a well-accessible, inexpensive, safe, and effective approach for IDA treatment. Almost all PO options are equally effective and safe. Gastrointestinal adverse effects are common and can sometimes limit further dosing.  Intravenous iron therapy is generally reserved for patients who are refractory or intolerant to PO treatment, have malabsorption of PO iron therapy, or have other health conditions such as chronic kidney disease, cancer, upcoming surgery, etc. Available IV options are equally effective and selection of an agent depends on insurance coverage, formulary inclusion, patient preference for test dose, frequency of dosing, etc.