Normally, your body carefully monitors your iron level and tries to keep it from rising too high or falling too low. This test can give your healthcare provider more information about health issues like anemia that are affecting your body's iron supply. You may need this test if your healthcare provider suspects that you have a certain type of anemia.
In general, anemia means you have a low number of red blood cells. One type of anemia is iron-deficiency anemia. If you have this type, you don't have enough iron to properly make hemoglobin. Hemoglobin is the substance that helps your red blood cells carry oxygen. Anemia usually happens because of blood loss or because you aren't absorbing enough iron from your food. Pregnant women are also at higher risk of developing this problem. Test results may vary depending on your age, gender, health history, the method used for the test, and other things.
Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. If you have a higher amount, you may have iron-deficiency anemia. If you have a lower level, you may have another problem, such as liver disease and hemolytic anemia. Science —, Because nonheme iron is poorly absorbed, dietary iron barely meets the daily requirement for most people. Even so, men who eat a typical Western diet are unlikely to become iron deficient solely as a result of dietary deficiency.
However, even modest losses, increased requirements, iatrogenic phlebotomy, or decreased caloric intake can contribute to iron deficiency. Blood loss is the major cause of iron deficiency.
In men and postmenopausal women, the most frequent cause is chronic occult bleeding, usually from the gastrointestinal tract eg, due to peptic ulcer disease Peptic Ulcer Disease A peptic ulcer is an erosion in a segment of the gastrointestinal mucosa, typically in the stomach gastric ulcer or the first few centimeters of the duodenum duodenal ulcer , that penetrates These vessels may cause recurrent bleeding, which is rarely In premenopausal women, cumulative menstrual blood loss mean, 0.
Intestinal bleeding due to hookworm infection Symptoms and Signs Ancylostomiasis is infection with the hookworm Ancylostoma duodenale or Necator americanus. Symptoms include rash at the site of larval entry and sometimes abdominal pain or other gastrointestinal Less common causes include urinary blood loss, recurrent pulmonary hemorrhage see Diffuse Alveolar Hemorrhage Diffuse Alveolar Hemorrhage Diffuse alveolar hemorrhage is persistent or recurrent pulmonary hemorrhage.
There are numerous causes, but autoimmune disorders are most common. Most patients present with dyspnea, cough, hemoptysis Increased iron requirements may contribute to iron deficiency. From birth to age 2 and during adolescence, when rapid growth requires a large iron intake, dietary iron often is inadequate.
During pregnancy, the fetal iron requirement increases the maternal iron requirement mean, 0. However, a disproportionate increase in plasma volume results in hemodilution Lactation also increases the iron requirement mean, 0. Decreased iron absorption can result from gastrectomy or malabsorption syndromes Overview of Malabsorption Malabsorption is inadequate assimilation of dietary substances due to defects in digestion, absorption, or transport.
Malabsorption can affect macronutrients eg, proteins, carbohydrates, fats Infection may be asymptomatic or result Symptoms depend on the length and The anemia is usually normocytic or macrocytic, and a dimorphic large and small population of circulating cells can be present. Rarely, absorption is decreased by dietary deprivation due to undernutrition. Most symptoms of iron deficiency are due to anemia. Such symptoms include fatigue, loss of stamina, shortness of breath, weakness, dizziness, and pallor.
In addition to the usual manifestations of anemia, some uncommon symptoms occur in severe iron deficiency. Other symptoms of severe deficiency include glossitis, cheilosis, and concave nails koilonychia.
Complete blood count CBC , serum iron, iron-binding capacity, serum ferritin, transferrin saturation, reticulocyte count, red cell distribution width RDW , and a peripheral blood smear. Iron deficiency anemia is suspected in patients with chronic blood loss or microcytic anemia, particularly if pica is present.
In such patients, a CBC, serum iron and iron-binding capacity, and serum ferritin and reticulocyte count are obtained see table Typical Serum Values for Iron, Iron-Binding Capacity, Ferritin, and Transferrin Saturation Typical Normal Serum Values for Iron, Iron-Binding Capacity,Ferritin, and Transferrin Saturation Iron deficiency is the most common cause of anemia and usually results from blood loss; malabsorption, such as with celiac disease, is a much less common cause.
Iron and iron-binding capacity and transferrin saturation are measured because their relationship is important. Various tests exist; the range of normal values relates to the test used and varies from laboratory to laboratory.
Serum iron level is low in iron deficiency and in many chronic diseases and is elevated in hemolytic disorders Overview of Hemolytic Anemia At the end of their normal life span about days , red blood cells RBCs are removed from the circulation.
Hemolysis is defined as premature destruction and hence a shortened RBC life span read more and in iron-overload syndromes Overview of Iron Overload Typical adults lose about 1 mg iron Fe per day in shed epidermal and gastrointestinal cells; menstruating females lose on average an additional 0. This iron loss The iron-binding capacity increases in iron deficiency, while the transferrin saturation decreases.
Serum ferritin levels closely correlate with total body iron stores. However, ferritin is an acute-phase reactant, and levels increase in inflammatory and infectious disorders eg, hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed The reticulocyte count is low in iron deficiency.
The peripheral smear generally reveals hypochromic red cells with significant anisopoikilocytosis, which is reflected in a high red cell distribution width RDW. The most sensitive and specific criterion for iron-deficient erythropoiesis is absent bone marrow stores of iron, although a bone marrow examination is rarely needed.
Stage 1 is characterized by decreased bone marrow iron stores; hemoglobin Hb and serum iron remain normal, but the serum ferritin level falls to During stage 2, erythropoiesis is impaired. Although the transferrin level is increased, the serum iron level decreases; transferrin saturation decreases.
Diagnosis of iron deficiency anemia prompts consideration of its cause, usually bleeding. Patients with obvious blood loss eg, women with menorrhagia may require no further testing. Men and postmenopausal women without obvious blood loss should undergo evaluation of the gastrointestinal GI tract, because anemia may be the only indication of an occult GI cancer.
Rarely, chronic epistaxis or genitourinary bleeding is underestimated by the patient and requires evaluation in patients with normal GI study results. Blood is drawn from a vein venipuncture , usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
Iron level can change, depending on how recently you ingested iron. Your health care provider will likely have you do this test in the morning or after fasting. Certain medicines may affect the results of this test.
Your provider will tell you if you need to stop taking any medicines. Do not stop any medicine before talking to your provider. When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging.
Afterward, there may be some throbbing or a slight bruise. This soon goes away. The numbers above are common measurements for results of these tests.
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