Haemoglobin Estimation

Haemoglobin estimation also known as Hg

Haemoglobin is a protein used by red blood cells to distribute oxygen to other tissues and cells in the body. It is made up of heme, which contains iron atoms plus the red pigment, porphyrin, (responsible for giving the blood it's red colour) and globin a chain of amino acids.

The test measures the amount of this substance in a specific volume of blood. It also indicates the amount of intracellular iron

Normal range
Varies with altitude.
Male - 8.1 to 11.2 mmol/L (13 to 18 gm/dL)
Female - 7.4 to 9.9 mmol/L (12 to 16 gm/dL)
Child - 7.1 to 8.4 mmol/L (11.5 to 13.5 gm/dL)
Newborns - 10.5 to 13.7 mmol/L (17 to 22 gm/dl)

What abnormal results mean:-

Decreased hemoglobin may indicate:
a) Anaemia of various types.
b) Blood loss - eg. from traumatic injury, surgery or bleeding colon cancer.
c) Gastrointestinal tract diseases resulting in blood loss eg. parasitic infections, colitis, haemorrhoids, ulcers.
d) Erythropoietin deficiency eg. from kidney disease.
e) Red blood cell destruction associated with transfusion reaction
f) Lead poisoning
g) Malnutrition and the associated nutritional deficiencies of iron, folic acid, vitamin B-12 & vitamin B-6
h) Overhydration - When more fluid is consumed than can be excreted. Often occurs in kidney disease or heart failure.
i) Bone marrow disorders eg. cancer or suppression by chemotherapy drugs.
j) Abnormal hemoglobin eg. sickle cell anaemia & thalassemia.
k) Women may have temporary decreases during menstrual periods and pregnancy.

Increased hemoglobin may indicate:
a) Dehydration - This can cause a falsely high hemoglobin reading which disappears when proper fluid balance is restored, eg, as in severe diarrhoea.
b)Polycythemia vera - a condition in which there is a long-term increase in red blood cells and other types of cells.
c) Macrocytosis - a situation where the red cells are larger than normal.
d) Malabsorption problem
e) Congenital heart disease
f) Lung Diseases eg:-
Emphysema
Severe asthma
pulmonary fibrosis - scarring of the lung.
cor pulmonale - failure of the right side of the heart caused by prolonged high blood pressure in the pulmonary artery and right ventricle of the heart.
g) Smokers may have elevated haemoglobin levels.
h) Adaptation to high altitudes.
i) Testosterone supplementation
j) Increased RBC formation associated with excess erythropoietin. Erythropoietin (EPO) is a hormone growth factor for red blood cells in the bone marrow.
A synthetic erythropoietin (Epogen) has been made that is used to treat anaemia due to kidney failure or chemotherapy.
However, although it is illegal, it is also used by athletes to increase their endurance.
k) Adrenal cortex overactivity.
l) Splenic hypofunction.

Important note for diabetics
Low Hemoglobin may cause the HgA1c test to give a false low.
High Hemoglobin may falsely elevate the results of the HgA1c.

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