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The Medical Clinics of North America May 1992Microcytic anemia is defined as the presence of small, often hypochromic, red blood cells in a peripheral blood smear and is usually characterized by a low MCV (less... (Review)
Review
Microcytic anemia is defined as the presence of small, often hypochromic, red blood cells in a peripheral blood smear and is usually characterized by a low MCV (less than 83 micron 3). Iron deficiency is the most common cause of microcytic anemia. The absence of iron stores in the bone marrow remains the most definitive test for differentiating iron deficiency from the other microcytic states, ie, anemia of chronic disease, thalassemia, and sideroblastic anemia. However, measurement of serum ferritin, iron concentration, transferrin saturation and iron-binding capacity, and, more recently, serum transferrin receptors may obviate proceeding to bone marrow evaluation. The human body maintains iron homeostasis by recycling the majority of its stores. Disruptions in this balance are commonly seen during menstruation, pregnancy, and gastrointestinal bleeding. Although the iron-absorptive capacity is able to increase upon feedback regarding total body iron stores or erythropoietic activity, this physiologic response is minimal. Significant iron loss requires replacement with iron supplements. The vast majority of patients respond effectively to inexpensive and usually well-tolerated oral iron preparations. In the rare circumstances of malabsorption, losses exceeding maximal oral replacement, or true intolerance, parenteral iron dextran is effective. In either form of treatment, it is necessary to replete iron stores in addition to correcting the anemia.
Topics: Anemia, Hypochromic; Diagnosis, Differential; Humans; Iron
PubMed: 1578956
DOI: 10.1016/s0025-7125(16)30339-x -
The New England Journal of Medicine Oct 2014
Review
Topics: Anemia; Anemia, Iron-Deficiency; Blood Transfusion; Erythrocytes; Ferritins; Ferrous Compounds; Humans; Inflammation; Iron; Risk Factors; Stem Cell Transplantation; Thalassemia
PubMed: 25271605
DOI: 10.1056/NEJMra1215361 -
FP Essentials Jul 2023Microcytic anemia is defined as anemia with a mean corpuscular volume (MCV) of less than 80 mcm3 in adults. Age-specific parameters should be used for patients younger...
Microcytic anemia is defined as anemia with a mean corpuscular volume (MCV) of less than 80 mcm3 in adults. Age-specific parameters should be used for patients younger than 17 years. The cause of microcytic anemia includes acquired and congenital causes, which should be considered separately according to the age of the patient, risk factors, and coexisting signs and symptoms. The most common cause of microcytic anemia is iron deficiency anemia; it can be managed with oral or intravenous iron, depending on the severity and comorbid conditions of the affected individual. Pregnant patients and patients with heart failure with iron deficiency anemia require special considerations to prevent significant morbidity and mortality. The wide spectrum of thalassemia blood disorders should be considered in patients with a particularly low MCV in the absence of systemic iron deficiency. Iron chelation may be required for some of these patients. Sickle cell anemia and sideroblastic anemia are important inherited causes of microcytic (as well as normocytic) anemia. Promising treatments are being developed for patients with transfusion-dependent thalassemia and sickle cell anemia.
Topics: Adult; Female; Pregnancy; Humans; Adolescent; Anemia, Iron-Deficiency; Anemia, Hypochromic; Anemia, Sickle Cell; Risk Factors
PubMed: 37390396
DOI: No ID Found -
American Family Physician Jun 2010Anemia is defined as a hemoglobin level of less than the 5th percentile for age. Causes vary by age. Most children with anemia are asymptomatic, and the condition is... (Review)
Review
Anemia is defined as a hemoglobin level of less than the 5th percentile for age. Causes vary by age. Most children with anemia are asymptomatic, and the condition is detected on screening laboratory evaluation. Screening is recommended only for high-risk children. Anemia is classified as microcytic, normocytic, or macrocytic, based on the mean corpuscular volume. Mild microcytic anemia may be treated presumptively with oral iron therapy in children six to 36 months of age who have risk factors for iron deficiency anemia. If the anemia is severe or is unresponsive to iron therapy, the patient should be evaluated for gastrointestinal blood loss. Other tests used in the evaluation of microcytic anemia include serum iron studies, lead levels, and hemoglobin electrophoresis. Normocytic anemia may be caused by chronic disease, hemolysis, or bone marrow disorders. Workup of normocytic anemia is based on bone marrow function as determined by the reticulocyte count. If the reticulocyte count is elevated, the patient should be evaluated for blood loss or hemolysis. A low reticulocyte count suggests aplasia or a bone marrow disorder. Common tests used in the evaluation of macrocytic anemias include vitamin B12 and folate levels, and thyroid function testing. A peripheral smear can provide additional information in patients with anemia of any morphology.
Topics: Adolescent; Age Factors; Anemia; Anemia, Iron-Deficiency; Anemia, Macrocytic; Blood Transfusion; Child; Child, Preschool; Erythrocyte Count; Erythrocyte Indices; Hemoglobins; Humans; Infant; Infant, Newborn; Iron; Reticulocyte Count; Risk Factors
PubMed: 20540485
DOI: No ID Found -
American Family Physician Oct 2018Anemia is associated with increased morbidity and mortality in older adults. Diagnostic cutoff values for defining anemia vary with age, sex, and possibly race. Anemia... (Review)
Review
Anemia is associated with increased morbidity and mortality in older adults. Diagnostic cutoff values for defining anemia vary with age, sex, and possibly race. Anemia is often asymptomatic and discovered incidentally on laboratory testing. Patients may present with symptoms related to associated conditions, such as blood loss, or related to decreased oxygen-carrying capacity, such as weakness, fatigue, and shortness of breath. Causes of anemia in older adults include nutritional deficiency, chronic kidney disease, chronic inflammation, and occult blood loss from gastrointestinal malignancy, although in many patients the etiology is unknown. The evaluation includes a detailed history and physical examination, assessment of risk factors for underlying conditions, and assessment of mean corpuscular volume. A serum ferritin level should be obtained for patients with normocytic or microcytic anemia. A low serum ferritin level in a patient with normocytic or microcytic anemia is associated with iron deficiency anemia. In older patients with suspected iron deficiency anemia, endoscopy is warranted to evaluate for gastrointestinal malignancy. Patients with an elevated serum ferritin level or macrocytic anemia should be evaluated for underlying conditions, including vitamin B12 or folate deficiency, myelodysplastic syndrome, and malignancy. Treatment is directed at the underlying cause. Symptomatic patients with serum hemoglobin levels of 8 g per dL or less may require blood transfusion. Patients with suspected iron deficiency anemia should be given a trial of oral iron replacement. Lower-dose formulations may be as effective and have a lower risk of adverse effects. Normalization of hemoglobin typically occurs by eight weeks after treatment in most patients. Parenteral iron infusion is reserved for patients who have not responded to or cannot tolerate oral iron therapy.
Topics: Aged; Aged, 80 and over; Anemia; Female; Ferrous Compounds; Humans; Male; Middle Aged; Physical Examination
PubMed: 30252420
DOI: No ID Found -
Pediatrics in Review Jan 2007
Review
Topics: Adolescent; Anemia; Anemia, Iron-Deficiency; Anemia, Sideroblastic; Child; Child, Preschool; Erythrocytes; Female; Hemoglobinopathies; Hemoglobins; Humans; Infant; Infant, Newborn; Inflammation; Lead Poisoning; Male; Medical History Taking; Physical Examination; Reference Values; Thalassemia
PubMed: 17197454
DOI: 10.1542/pir.28-1-5 -
The Medical Clinics of North America Mar 2017Anemia is among the most common medical problems and clinical and laboratory evaluation need to be approached logically. The complete blood count with red cell indices... (Review)
Review
Anemia is among the most common medical problems and clinical and laboratory evaluation need to be approached logically. The complete blood count with red cell indices offers clues to diagnosis. Many anemias have characteristic red cell morphology. The reticulocyte count serves as a useful screen for hemolysis or blood loss. Testing for specific causes of the anemia is performed. Occasionally, examination of the bone marrow is required for diagnosis. Molecular testing is increasingly being use to aid the diagnostic process. This article reviews diagnostic tests for anemia and suggests a rational approach to determining the etiology of a patient's anemia.
Topics: Anemia; Blood Cell Count; Bone Marrow Cells; Cytogenetic Analysis; Diagnosis, Differential; Erythrocyte Indices; Hematologic Tests; Humans
PubMed: 28189170
DOI: 10.1016/j.mcna.2016.09.003 -
Polish Archives of Internal Medicine May 2017Anemia is a frequent, although often underestimated, clinical condition accompanying thyroid diseases. Despite the fact that anemia and thyroid dysfunction often occur... (Review)
Review
Anemia is a frequent, although often underestimated, clinical condition accompanying thyroid diseases. Despite the fact that anemia and thyroid dysfunction often occur simultaneously, the causative relationship between the disorders remains ambiguous. Thyroid hormones stimulate the proliferation of erythrocyte precursors both directly and via erythropoietin production enhancement, while iron-deficient anemia negatively influences thyroid hormone status. Thus, different forms of anemia might develop in the course of thyroid dysfunction. Normocytic anemia is the most common, while macrocytic or microcytic anemia occurs less frequently. Anemia in hypothyroidism might result from bone marrow depression, decreased erythropoietin production, comorbid diseases, or concomitant iron, vitamin B12, or folate deficiency. Altered iron metabolism and oxidative stress may contribute to anemia in hyperthyroidism. The risk of anemia in autoimmune thyroid disease (AITD) may be related to pernicious anemia and atrophic gastritis, celiac disease, autoimmune hemolytic syndrome, or rheumatic disorders. The coexistence of anemia and thyroid disease constitutes an important clinical problem. Thus, the aim of this review was to provide a comprehensive summary of data on the prevalence, potential mechanisms, and therapy of anemia in the course of thyroid diseases from the clinical and pathogenetic perspectives. Thyroid dysfunction and AITD should be considered in a differential diagnosis of treatment-resistant or refractory anemia, as well as in the case of increased red blood cell distribution width. Of note, the presence of AITD itself, independently from thyroid hormone status, might affect the hemoglobin level.
Topics: Anemia; Female; Humans; Male; Thyroid Diseases; Thyroid Hormones
PubMed: 28400547
DOI: 10.20452/pamw.3985 -
Clinics in Laboratory Medicine Jun 2013Hemodynamic changes occur in pregnancy to prepare for expected blood loss at delivery. Physiologic anemia occurs in pregnancy because plasma volume increases more... (Review)
Review
Hemodynamic changes occur in pregnancy to prepare for expected blood loss at delivery. Physiologic anemia occurs in pregnancy because plasma volume increases more quickly than red cell mass. Anemia is most commonly classified as microcytic, normocytic, or macrocytic. Iron deficiency anemia accounts for 75% of all anemias in pregnancy. Oral iron supplementation is the recommended treatment of iron deficiency anemia in pregnancy. Parenteral iron and erythropoietin can also be used in severe or refractory cases. Outcomes and treatments for other forms of inherited and acquired anemias in pregnancy vary by disease, and include nutritional supplementation, corticosteroids, supportive transfusions, and splenectomy.
Topics: Anemia; Female; Humans; Pregnancy; Pregnancy Complications, Hematologic
PubMed: 23702118
DOI: 10.1016/j.cll.2013.03.016 -
American Family Physician Mar 2007The prevalence of iron deficiency anemia is 2 percent in adult men, 9 to 12 percent in non-Hispanic white women, and nearly 20 percent in black and Mexican-American... (Review)
Review
The prevalence of iron deficiency anemia is 2 percent in adult men, 9 to 12 percent in non-Hispanic white women, and nearly 20 percent in black and Mexican-American women. Nine percent of patients older than 65 years with iron deficiency anemia have a gastrointestinal cancer when evaluated. The U.S. Preventive Services Task Force currently recommends screening for iron deficiency anemia in pregnant women but not in other groups. Routine iron supplementation is recommended for high-risk infants six to 12 months of age. Iron deficiency anemia is classically described as a microcytic anemia. The differential diagnosis includes thalassemia, sideroblastic anemias, some types of anemia of chronic disease, and lead poisoning. Serum ferritin is the preferred initial diagnostic test. Total iron-binding capacity, transferrin saturation, serum iron, and serum transferrin receptor levels may be helpful if the ferritin level is between 46 and 99 ng per mL (46 and 99 mcg per L); bone marrow biopsy may be necessary in these patients for a definitive diagnosis. In children, adolescents, and women of reproductive age, a trial of iron is a reasonable approach if the review of symptoms, history, and physical examination are negative; however, the hemoglobin should be checked at one month. If there is not a 1 to 2 g per dL (10 to 20 g per L) increase in the hemoglobin level in that time, possibilities include malabsorption of oral iron, continued bleeding, or unknown lesion. For other patients, an endoscopic evaluation is recommended beginning with colonoscopy if the patient is older than 50.
Topics: Administration, Oral; Algorithms; Anemia, Iron-Deficiency; Diagnosis, Differential; Female; Ferric Compounds; Ferritins; Humans; Infusions, Parenteral; Iron; Male; Risk Factors; Transferrin
PubMed: 17375513
DOI: No ID Found