Sickle-cell disease is a group of inherited blood disorders where an abnormality in the oxygen-carrying hemoglobin protein in red blood cells (RBCs) causes them to take on a rigid, sickle shape under certain conditions. This leads to problems like anemia, swelling of hands and feet, and bacterial infections starting around 5-6 months of age. The sickling of RBCs damages their cell membranes over time, decreasing elasticity and causing rigid cells that cannot pass through small blood vessels, leading to vessel blockages and tissue ischemia.

1. Sickle-cell disease (SCD) is a group of blood disorders
typically inherited from a person's parents. The most
common type is known as Sickle-cell anaemia (SCA). It
results in an abnormality in the oxygen-carrying
protein, haemoglobin present in RBCs. This leads to a
rigid, sickle-like shape under certain circumstances.
Problems typically begin around 5-6 months of age.
The problems involve anaemia, swelling in hands and
feet, bacterial infections etc.

2. Normal RBCs are quite elastic, which allows
them to deform while passing through
capillaries.
In sickle cell anaemia, low oxygen tension
promotes sickling of RBCs and repeated
episodes of sickling damage the cell membrane
leading to decrease in cell elasticity.

3. The cells return to normal shape
when oxygen tension is restored.
Rigid RBCs are unable to pass
through narrow capillaries, leading
to vessel occlusion and ischaemia.

4. The actual anaemia is caused by
haemolysis.
Healthy RBCs typically function
for 90-120 days; while sickle cells
last only for 10-20 days.

5. Fatigue and Anemia
 Pain Crises and Dactylitis (swelling and
inflammation of the hands and/or feet)
Arthritis
Bacterial Infections
Splenic sequestration (sudden pooling of
blood in the spleenand Liver Congestion )

6. Lung and Heart Injury
 Leg Ulcers
 Aseptic necrosis and bone infarcts
(death of portions of bone)
Eye damage

7. The loss of red blood cell elasticity is
central to the pathophysiology of
sickle cell anemia. Normal red blood
cells are quite elastic, which allows
the cells to deform to pass through
capillaries.

8. In sickle cell anemia, low-oxygen
tensions promotes red blood cell
sickling and repeated episodes of
sickling damage the cell membrane
and decrease the cell's elasticity. These
cells fail to return to normal shape
when normal oxygen tension is
restored

9. As a consequence, these rigid
blood cells are unable to deform
as they pass through narrow
capillaries, leading to vessel
occlusion and ischaemia.