Description

• Deficiency in red blood cells, hemoglobin, or blood volume due to decreased iron stores
• Onset may be acute, with rapid blood loss, or chronic, with nutrition derangement or slow blood loss.
• System(s) affected: Heme; Lymphatic; Immunologic
• Synonym(s): Anemia of chronic blood loss; Hypochromic; Microcytic anemia; Chlorosis

Geriatric Considerations
60% of anemias occur in people >65 years of age.

Pediatric Considerations
Problematic in infants whose major source of nutrition is unfortified cow's milk and/or juices

Pregnancy Considerations
Iron supplements (15–30 mg/d) are recommended during pregnancy.

Epidemiology

• Iron deficiency anemia (IDA) is the most common cause of anemia in the US.
• Predominant age: All ages, but especially toddlers and menstruating women
• Predominant sex: Female > Male
• More likely in the poor and in underimmunized children

• Adults: Men 2%, women 15–20% annually
• Infants and toddlers: 3–5% annually
• Pregnant patients: Unclear; maybe as high 20% (pseudoanemia common during pregnancy as plasma volume expands faster than red cell mass)

• Infants and children age <12 years: 4–7% (1)
• Men: 2–5% (1)
• Women: 9–16% (18–50% in menstruant blood donors) (1,2)

Risk Factors

• Premenopausal woman
• Frequent blood donor
• Pregnancy and breastfeeding
• Strict vegan diet
• Use of NSAIDs

General Prevention

• Screen asymptomatic pregnant women (3)[B].
• Supplementation in asymptomatic children aged 6–12 months if at risk for IDA (e.g., malnutrition, abuse, cow's milk <12 months) (3)[B]

Pathophysiology

Depletion of iron stores leads to decrease in both reticulocyte count and production of hemoglobin.

Etiology

• Blood loss (e.g., menses, GI bleeding, trauma)
• Poor iron intake
• Poor iron absorption (e.g., atrophic gastritis, postgastrectomy, celiac disease)
• Increased demand for iron (e.g., infancy, adolescence, pregnancy, and breastfeeding)

Commonly Associated Conditions

• GI tract malignancy, peptic ulcer disease (PUD), Helicobacter pylori infection, irritable bowel disease
• Hookworm or other parasitic infestations
• Hypermetrorrhagia
• Pregnancy