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Blood Donation
Blood Donation Blood is connective tissue. It circulates in closed blood vessels in the system. The circulating blood consists of erythrocytes (red blood cells), leucocytes (white blood cells), and platelets or thrombocytes in a pale yellow colored fluid called plasma. When blood is given to a pathological lab for routine check up of blood CBC – a complete blood count is performed.
It is performed generally by two methods the Sahli method or the cyanmethemoglobin method:

Normal Values Hb, g/dl
Men 14 – 18
Women 11.5 – 16.5
Children (up to 1 year) 11.0 – 13.0
Children (10 – 12 years) 11.5 – 14.5
Infants (full term cord blood) 3.5 – 19.5

  • Decrease in hemoglobin below the normal range indicates anemia.
  • It also drops in pregnancy due to hemodilution.
  • An increase is also seen in congenital heart disease due to reduced oxygen supply.
  • An increase in hemoglobin in emphysema.
  • An increase in hemoglobin in polycythemia.
Normal Erythrocyte Normal values:
  • Male – 4.5 to 6.0 x 106 cells/cu mm (ml)
  • Female – 4.0 to 4.5 x 106 cells/cu mm (ml)
  • At birth – 6.5 to7.25 x 106 cells/cu mm (ml)
  • A decrease in RBC count as also observed in old age, in pregnancy and in diseases which cause anemia.
  • An increase in the RBC count is observed in burns and cholera due to fluid loss.
  • An increase in the RBC count is also observed in chronic heart disease, emphysema and polycythemia.
  • Sometimes, false low counts can be due to edema, an error in calculation or due to improper dilution by the technician.
  • Sometimes, false high counts can be due to hemoconcentration, an error in calculation or due to an improper technique used by the technician.
  • Normal values:
    Adults 4,000 – 10,000/cu mm (ml).
    At birth 10,000 – 25,000/cu mm (ml).
    1 to 3 years 6,000 – 18,000/cu mm (ml).
    4 to 7 years 6,000 – 15,000/cu mm (ml).
    8 to 12 years 4,500 – 13,500/cu mm (ml).
    If there is an increase in the total WBC count and it is more than 10,000/cu mm (ml), it is known as leucocytosis.

    Causes of Leucocytosis
    • It occurs due to bacterial, viral, protozoal (malaria) or parasitic (filaria, hook worm) infections.
    • It is also observed in severe hemorrhage and in leukemia.
    Abnormal leucocyte
    • At birth, the count is high and about 18,000/cu mm (ml), It gradually drops.
    • In full–term pregnancy, it goes to 12,000 to 15,000/cu mm (ml). It rises soon after delivery, and then returns to normal gradually.
    • Due to high temperature.
    • Due to severe pain.
    • Due to muscular exercise.
    If there is a decrease in WBC count and it falls to less than 4,000/cu mm (ml), it is known as leucopenia.
    Causes of Leucopenia
    • Bacterial infections like typhoid, paratyphoid, tuberculosis etc. reduces the count.
    • Viral infections like hepatitis, influenza, and measles also reduce the count.
    • Protozoal infections like malaria reduce the count.
    • Leukemia does it too.
    • Primary bone marrow depression (aplastic anemia).
    • Secondary bone marrow depression (due to drugs, radiation etc.).
    • Anemia (iron deficiency, megaloblastic etc.)
    Platelets are very small in diameter – around 3 mm. They help in clotting of blood. Normal platelet count is 250,000 to 500,000/cu mm (ml) and it is said to be adequate. If it is less than that, it is said to be inadequate.
    In various types of anemia and in other diseases such as thalassemia, malaria, kidney failure etc., the mature RBCs show significant changes. Various changed RBCs seen are termed as microcytes, macrocytes, hypochromic, spherocytes, target cells, stomatocytes, anisocytosis, poilkilocytosis, sickle cells, ovalocytes, elliptocytes, acanthocytes, burr cells, siderocytes, basophilic stippling, howell–jolly body, cobot ring, schi stocytes, crescent bodies and creneted cells depending upon their morphology.
    PCV (packed cell volume) is the amount of packed red blood cells after centrifugation. It is expressed in the percentage of total blood volume.
    Normal values
    Male: 42–52%.
    Female: 36–48%.
    Late pregnancy: 23–37%.
    Increase in PCV is due to polycythemia, dehydration, emphysema, and congenital heart disease.
    Decrease in PCV is due to different types of anemia, hydremia (excessive fluid in the blood which occurs in pregnancy).
    MCV – Mean Cell Volume
    • Normal value: 82–92 cu mm.
    • Increased MCV indicates macrocytic anemias.
    • Decreased MCV indicates microcytic anemias.
    MCH – Mean Cell hemoglobin
    • Normal value: 27–32 pg (pg = 1 picogram = 10–12 g).
    • Increased value indicates macrocytic anemia.
    • Decreased value indicates hypochromia.
    It is average amount of hemoglobin in the red cell compared to normal.
    • Normal color index: 0.85–1.15.
    • Increase in the color index indicates megaloblastic anemias.
    • Decrease in the color index indicates hypochromic anemia.
    Blood parasites cause a number of ailments which are more prevalent in tropical counties. The common diseases caused are malaria, kala azar and sleeping sickness.
    Plasmodium Falciparum (Click on image to large view) The parasites found are:
    A) The following parasites cause malaria
    • Plasmodium vivax.
    • Plasmodium malariae.
    • Plasmodium falciparum.
    • Plasmodium ovale.
    B) The following parasites cause visceral leishmaniasis, dumdum fever or kala azar
    • Leishmania donovani.
    C) The following parasites cause African sleeping sickness
    • Trypanosoma brucei gambiense.
    D) The following parasites cause filaria
      Mansonella ozzardi Wuchereria bancrofti Lao loa
      Mansonella ozzardi Wuchereria bancrofti Lao loa

    • Wuchereria bancrofti.
    • Mansonella perstans.
    • Brugia timori.
    • Mansonella ozzardi.
    • Brugia malayi.
    • Lao loa.
    Normal Value: 32–36%.
    • Increased value indicates spherocytosis.
    • Decreased value indicates hypochromic anemias.
    Blood Routine – Normal Values

    Test Normal Values
    Hemoglobin Men 13.5–17.5%
    Women 11.5–16.5%
    Total WBC Count Adults: 4000–11000/
    Differential Count Neutrophils 40–75%
    Eosinophils 1–6%
    Lymphocytes 20–45%
    Monocytes 2–10%
    Basophils 0–1%
    ESR: (Westegren): 1 hr Men 1–10 mm
      Women 5–15 mm
    Platelet Count 1.5–4.0 lakhs/
    Reticulocyte Count Adults: 0.2–2%
    RBC (Erythrocyte) Count Men 4.5–6.5 million/
    Women 3.8–5.8 million/
    Mean Corpuscular Volume 75–97 fl
    Mean Corpuscular Hemoglobin 26–33 pg
    Mean Corpuscular Hemoglobin Concentration 32–35%
    Haematocrit (PCV) Men 40–54%
    Women 37–47%
    It means stretching of body tissue due to the accumulation of gas or air in the tissue or organ. Pulmonary emphysema is a chronic lung disease in which air sacs of the lungs are stretched until the elastic fibers in them are destroyed.
    It is an excess of red blood cells. It may be temporary due to lack of oxygen in the blood. It may be due to heart disease or continued exposure to high altitudes. Also, if may be due to disorder of the bone marrow.
    Myeloid leukemia
    It is a kind of blood cancer.
    Congenital heart disease
    It means any heart disorder that is present at birth. Most common is a hole between two ventricles, either narrowing or the wrong position of the aorta (the main artery), or constriction of valves on the left side of the heart with weakness of the heart muscle.
    Aplastic anemia
    It is a disease of the bone marrow. It produces deficiency of the red blood cells, white blood cells as well as platelets.
    Infectious mononucleosis

    Also called glandular fever caused by a herpes virus (Ebstein–Barr virus).
    Megaloblastic anemia
    It is a disease of the bone marrow. Here, immature abnormal red blood cells are found in the blood.
    Swelling of any part of the body due to retention of fluids.
    Sub–acute bacterial endocarditis
    Endocarditis means inflammation of the endocardium, the inner lining of the heart. When bacteria infects it, then it is called bacterial endocarditis. All types of endocarditis, if untreated are fatal.
    Microcytic anemia
    A decrease in red blood cells, reduced hemoglobin, PCV, MCV, MCH and MCHC.
    Macrocytic anemia
    A decrease in red blood cells, reduced, hemoglobin, elevated MCH and MCV with normal MCHC.