Anaemia is defined as a reduced haemoglobin concentration below normal levels for age and sex. In adults, normal haemoglobin levels are 13.0 g/dl for males and 11.5g/dl for females. When haemoglobin levels are subnormal, the oxygen-carrying capacity of the blood is lowered, which causes compensatory physiological adaptations like increased oxygen release from haemoglobin, increased blood flow to tissues, maintenance of blood volume, and redistribution of blood flow to the brain.

1. ANAEMIA
PATHOPHYSIOLOGY
Anaemia is defined as reduced haemoglobin concentration in blood below
the lower limit of the normal range for the age and sex of individual.
In adults,the lower extreme of the normal haemoglobin is taken as 13.0 g/dl
for males and 11.5g/dl for females.
Subnormal level of haemoglobin causes lowered oxygen-carrying capacity of the blood.
This in turn, initiates compensatory physiologic adaptations such as follows;
(1)Increased release of oxygen from haemoglobin
(2)Increased blood flow to the tissues
(3)Maintenance of the blood volume
(4)Redistribution of blood flow to maintain the cerebral
blood supply