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What is sickle cell anaemia?

Sickle cell anaemia is a genetic (passed from parent to child) disorder that affects the body's blood cells. In this disease, faulty haemoglobin (a substance that carries oxygen in the blood) causes the red blood cells to change shape when oxygen is released to tissues.

Sickle cell genes are most commonly found in people of African-Caribbean descent. Carrying the genes doesn’t mean a person will be affected by sickle cell anaemia.

The disease gets its name because the faulty blood cells are shaped like sickles - old farming tools used to cut wheat. When the deformed cells go through blood vessels, they clog the blood flow and can break apart.

Sickle cells can cause pain, damage the blood vessels or other areas of the body and cause anaemia (low blood count).

Sickle cell anaemia is found most often in black people. However, other ethnic groups also can have sickle cell disease. Antenatal screening can be offered if family origin suggests a risk for the condition. 

What causes sickle cell disease?

Normal red blood cells are round and are able to move through small blood vessels in the body to deliver oxygen. In sickle cell anaemia, a chemical change in haemoglobin causes the substance to form long rods in the red blood cell as the haemoglobin releases oxygen. These rigid rods change the shape of the red blood cell into a sickle shape.

Sickle cell anaemia is not contagious. Children are born with sickle cell haemoglobin, which they inherit from their parents. Individuals may be carriers who have sickle cell trait or may actually have sickle cell disease. People who inherit only one sickle cell gene are carriers, but people who inherit two sickle cell genes have sickle cell disease.

What are the symptoms of sickle cell anaemia?

Sickle cell anaemia can cause a painful sickle cell crisis. A sickle cell crisis is also known as a vaso-occlusive episode (VOE).

Other symptoms of sickle cell disease include:

• Fatigue
• Anaemia
• Swelling and inflammation of the joints 
• Sickling crisis - blood blockage in the spleen or liver

Sickle cell anaemia can also cause damage to the heart, lungs, kidneys and bones 

How is sickle cell anaemia diagnosed?

Sickle cell anaemia is diagnosed by examining a sample of blood under a microscope. When the abnormal sickle-shaped cells in the blood are identified, a diagnosis is made. Also, a blood test called the haemoglobin electrophoresis can determine if a person has the disease or is a carrier.

How is sickle cell anaemia treated?

The only cure for sickle cell anaemia is a bone marrow transplant, where affected bone marrow is replaced with bone marrow from somebody who does not have the condition.

National Institute for Health and Care Excellence (NICE) guidelines for England for the management of acute painful sickle cell episodes in hospital say:

• A thorough assessment of people who go to hospital with an acute painful sickle cell episode is needed to ensure they have an accurate diagnosis and are given appropriate pain relief within 30 minutes.
• People with an acute painful sickle cell episode should have an assessment of pain relief every 30 minutes until satisfactory pain relief has been reached, and then at least every 4 hours.
• Acute chest syndrome (ACS) is a major cause of death in people with sickle cell disease and is often missed as a possible complication. People with an acute painful sickle cell episode should be assessed for acute chest syndrome if they have symptoms such as abnormal respiratory symptoms, chest pain, fever, or signs and symptoms of hypoxia.