anemia%20-%20iron-deficiency
ANEMIA - IRON-DEFICIENCY
Anemia is a condition wherein the blood has low levels of red blood cells (RBC), hemoglobin (oxygen-carrying pigment in whole blood) and/or hematocrit (intact RBC in blood) making it insufficient to address the physiologic needs of the body.
Iron-deficiency anemia is the anemia that resulted from inadequate iron supplementation or excessive blood loss.
It is the most common nutritional disorder worldwide and accounts for more than half of anemia cases.
It is prevalent among preschool children and pregnant women.

Definition

  • A condition wherein the blood has low levels of red blood cells (RBC), hemoglobin (oxygen-carrying pigment in whole blood) or hematocrit (intact RBC in the blood) making it insufficient to address the physiologic needs of the body
  • Based on WHO, anemia is having hemoglobin concentration:
    • Men (>15 years old): <13 g/dL
    • Women (non-pregnant, >15 years old): <12 g/dL
    • Women (pregnant): <11 g/dL (declines to 0.5 g/dL in the 2nd trimester of pregnancy)
    • Children (12-14 years old): <12 g/dL
    • Children (5-11 years old): <11.5 g/dL
    • Children (6 months - 4 years old): <11 g/dL

Etiology

Causes of Anemia

  • Normocytic anemia when RBC morphology is unremarkable 
    • Blood loss - most common cause
    • Decreased RBC production due to low RBC production or destruction of precursors of RBC within the bone marrow, eg chronic disease
    • Increased RBC destruction, eg hemolysis
  • Macrocytic anemia wherein the RBC is larger than the nucleus of a small lymphocyte on a peripheral smear due to:
    • Megaloblastic causes: Folate and vitamin B12 deficiency, HIV infection, rare inborn errors of metabolism, myelodysplastic syndrome or congenital dyserythropoietic anemia
    • Nonmegaloblastic causes: Marked reticulocytosis, aplastic anemia, abnormal nucleic acid metabolism of erythroid precursors interfering with nucleic acid synthesis, abnormal RBC maturation, other causes such as Down syndrome, alcohol abuse, liver disease and hypothyroidism
  • Microcytic anemia when RBCs appear smaller due to the following pathologic processes:
    • Reduced iron availability/iron-deficiency anemia
    • Acquired disorders of heme synthesis, eg thalassemia 
    • Reduced globin production
    • Rare congenital disorders including sideroblastic anemias, porphyria, and defects of iron absorption transport, utilization and recycling
    • Inflammation or chronic disease
    • Lead poisoning

Signs and Symptoms

  • Primary symptoms include: Dyspnea (exertional or at rest), fatigue, palpitations, headache, faintness or lightheadedness, tinnitus, anorexia, gastrointestinal (GI) disturbances, loss of libido
  • Symptoms of severe anemia include: Lethargy, confusion, tachycardia, retinal hemorrhage that may lead to life-threatening complications such as congestive heart failure, angina, arrhythmia and/or myocardial infarction
  • Symptoms can be due to decreased oxygen delivery to tissues and in patients with acute and marked bleeding, the added insult of hypovolemia
Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS JPOG - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
Pearl Toh, 07 Aug 2018
A home-based, self-applied wearable electrocardiogram (ECG) patch facilitates diagnosis of atrial fibrillation (AF) among high-risk individuals, according to the mSToPS* trial.
Roshini Claire Anthony, 3 days ago

A genotype-guided approach to warfarin dosing may result in fewer dose adjustments in Asian patients, according to a study from Singapore.

6 days ago

Fungal microbiome, also called the mycobiome, appears to be highly variable in patients with well-characterized fungal diseases, a recent study has shown. Moreover, severe asthmatics have the highest fungal loads, along with those receiving steroid and antifungal therapy.

Tristan Manalac, 5 days ago
The risk of complicated appendicitis is lower in children with IgE-mediated allergy, according to a recent study.