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What is polycythemia?

Polycythemia is the excessive amount of RBC mass that leads to redness of conjunctiva, mucous membrane, skin and nailbed .
Polycythemia may be primary or secondary
Primary polycythemia 
Primary polycythemia  is a proliferative polycythemia is the malignant counterpart.
Secondary polycythemia 
Is a condition where you get it secondary to some systemic cause
This may be often accompanied by central cyanosis and clubbing as seen in congenital cyanotic heart disease and interstitial lung disease .This is called as secondary polycythemia
Laboratory criteria for polycythemia
In males
  • RBC mass is > 36 ml/kg
  • PCV > 55 %
In females
  • RBC mass > 32 ml/kg
  • PCV > 47 %
How to detect polycythemia?
Polycythemia is examined in the same manner as anemia.Examine the lower palpebral conjunctiva, longue, soft palate, nail beds, palms and soles, and general skin surface.The colour of the mucous membrane turns dusky-red. Patients with  polycythemia usually have facial plethora  and suffused conjunctiva, increased redness of lower palpebral conjunctiva and palmar erythema.
What are the common causes of polycythemia? 
  • COPD.
  • Congenital cyanotic heart diseases e.g. Fallot's tetralogy.
  • Right-to-lcft shunt in the heart.
  • Polycythemia rubra vera.
  • High altitude and severe dehydration  can produce relative polycythemia
Thrombosis and peptic ulceration (often with bleeding) are noted complications of polycythemia.
What is normal reticulocyte count. reticulocyte index and red cell mass 
Reticulocyte count- 0.2-2% of RBCs (increased in haemolyttc anaemia).
Reticulocyte Index— Reticulocyte % X Patient's PCV/Normal PCV
Red cell mass-in males Male is 30ml/kg of body weight.
Female - 25 ml/kg of body weight.
It is increased in polycythemia rubra vera