06/07/2026
Sickle Cells (Sickle Cell Disease) – Complete Overview
What is Sickle Cell Disease?
Sickle Cell Disease is a genetic blood disorder that affects red blood cells. Instead of being round and flexible, some red blood cells become crescent-shaped ("sickle-shaped"), making it harder for them to move through blood vessels.
Cause
Sickle cell disease is caused by a mutation in the HBB gene, which produces hemoglobin (the protein that carries oxygen in red blood cells).
Inheritance
Sickle Cell Trait (AS): One normal gene and one sickle gene.
Usually healthy.
Can pass the gene to children.
Sickle Cell Disease (SS): Two sickle genes inherited (one from each parent).
Causes symptoms and complications.
Risk Groups
Most common among people with ancestry from:
Sub-Saharan Africa
India
Middle East
Mediterranean regions
Caribbean countries
What Happens in the Body?
Normal red blood cells:
Round
Flexible
Live about 120 days
Sickle cells:
Rigid and sticky
Can block blood vessels
Break apart easily
Live only 10–20 days
This leads to:
Reduced oxygen delivery
Anemia
Pain crises
Organ damage
Symptoms
In Infants
Swelling of hands and feet (dactylitis)
Irritability
Fever
Common Symptoms
Fatigue
Weakness
Pale skin
Shortness of breath
Rapid heartbeat
Delayed growth
Pain Crises (Vaso-Occlusive Crisis)
The most common symptom.
Occurs when sickled cells block blood flow.
Pain may affect:
Bones
Chest
Abdomen
Joints
Back
Pain episodes can last:
Hours
Days
Weeks
Complications
Acute Chest Syndrome
A medical emergency causing:
Chest pain
Fever
Difficulty breathing
Low oxygen levels
Stroke
Blocked blood flow to the brain can cause stroke, especially in children.
Infections
People with sickle cell disease are more prone to infections because the spleen may become damaged.
Organ Damage
Can affect:
Kidneys
Liver
Lungs
Heart
Eyes
Other Complications
Gallstones
Leg ulcers
Priapism (prolonged painful er****on)
Pulmonary hypertension
Diagnosis
Newborn Screening
Many countries routinely screen newborns.
Blood
