Iron Deficiency Anemia Calculator

Background Info

Overview:
Anemia is defined as a decrease in the total amount of red blood cells (RBCs) or hemoglobin in the blood and is present when it falls below certain thresholds depending on the age, gender, and race of the patient.   Based on WHO criteria, the lower limit of normal in adults is 13 g/dL in men and 12 g/dL in women. The blood hemoglobin concentration may more accurately indicate the total red cell mass compared with the hematocrit.

Iron-deficiency anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood due to a decrease in iron and is estimated to cause approximately half of all anemia cases globally.  Iron is a critical component of hemoglobin and about 70% of the iron found in the body is bound to hemoglobin.  Iron is primarily absorbed in the small intestine This type of anemia may be related to blood loss ( uterine fibroids, stomach ulcers, colon cancer, urinary tract bleeding, other sources),  insufficient dietary intake, or poor absorption of iron from food (may occur as a result of an intestinal disorder such as inflammatory bowel disease or celiac disease, or surgery such as a gastric bypass).

Sources of iron:
Iron deficiency anemia can be prevented by eating a diet containing sufficient amounts of iron or by iron supplementation.  Foods high in iron include meat, nuts, spinach, and foods made with iron-fortified flour. 

Symptoms vary greatly and depend on the onset and the individual's ability to compensate for a loss in oxygen-carrying capacity.  Anemia with a slow onset may go undetected or present with vague symptoms including tiredness, weakness, shortness of breath, poor concentration or reduced exercise tolerance.  Anemia that occurs rapidly often has more obvious symptoms such as confusion, mental status changes, lightheadedness, loss of consciousness, palpitations, respiratory distress, or hypotension.  Symptoms are often more severe if there is underlying coronary artery disease, congestive heart failure, or  intrinsic pulmonary or cerebrovascular disease. Typical signs exhibited may include pallor (pale skin, lining mucosa, conjunctiva and nail beds), however, further testing is required to confirm the diagnosis.

Other possible symptoms and signs include:

• Irritability
  
• Angina (chest pain)
  
• Tingling, numbness, or burning sensations
  
• Glossitis (inflammation or infection of the tongue)
  
• Angular cheilitis (inflammatory lesions at the mouth's corners)
  
• Koilonychia (spoon-shaped nails) or nails that are brittle
  
• Poor appetite
  
• Dysphagia (difficulty swallowing)
  

References

1. Alldredge BK, Corelli RL, Ernst ME, Guglielmo BJ, eds. Anemias. In: Koda-Kimble & Young's Applied Therapeutics: The Clinical Use of Drugs. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins;2013;303-307.
   
   
2. Beata I, Mason BJ, and Thompson EG. Anemias. In: DiPiro JT, Talbert RL, Yee GC, et al, eds. Pharmacotherapy: A Pathophysiologic Approach. 6th ed. New York, NY: McGraw-Hill Inc; 2005:1806-1817.
   
   
3. Cook JD. Diagnosis and management of iron-deficiency anaemia. Best Pract Res Clin Haematol 2005;18:319-32.
   
   
4. Killip S, Bennett JM, Chambers MD. Iron deficiency anemia. Am Fam Physician. 2007 Mar 1;75(5):671-8. [Pubmed]
   
   
   
5. Lopez A, Cacoub P, Macdougall IC, Peyrin-Biroulet L. Iron deficiency anaemia. Lancet. 2016 Feb 27;387(10021):907-16. doi: 10.1016/S0140-6736(15)60865-0. Epub 2015 Aug 24.
   
   
6. Wians FH Jr, Urban JE, Keffer JH, Kroft SH. Discriminating between iron deficiency anemia and anemia of chronic disease using traditional indices of iron status vs transferrin receptor concentration. Am J Clin Pathol. 2001 Jan;115(1):112-8.  [Pubmed]
   
   
7. Zarychanski, R; Houston, DS (Aug 12, 2008). "Anemia of chronic disease: a harmful disorder or an adaptive, beneficial response?". CMAJ : Canadian Medical Association Journal. 179 (4): 333–7. [Pubmed]