What is Sickle Cell?

Red blood cells

Sickle Cell is the name for a group of different but similar inherited health conditions that affect hemoglobin.  It  is the most common and the fastest growing genetic condition in the UK. Sickle Cell gets its name because the red blood cells - which are normally round and flexible - become shaped like a crescent moon or farmer’s sickle. The unusually-shaped red blood cells are rigid and they can block blood vessels. This reduces the blood flow to that part of the body resulting in excruciating pain known as a Sickle Cell crisis.  This can sometimes cause damage.

Sickle Cell can cause the following symptoms:  

  • Sickle Cell crisis
  • Stroke (common between the ages of 2 and 16)
  • Blindness
  • Organ failure
  • Pulmonary hypertension
  • Acute chest syndrome
  • Leg ulcers
  • Gallstones
  • Headaches

There are different types of Sickle Cell

These depend on the genes a baby inherits from their parents. All babies are now tested for Sickle Cell in their first week of life using a spot of blood taken from a heel-prick. There are over 1000 different types of unusual hemoglobin but the ones that are most commonly seen in the UK are hemoglobin S, hemoglobin C, hemoglobin D and beta thalassaemia. Did you know it is estimated that 1 in 7 adults of African and Caribbean descent in the UK carry the Sickle Cell gene. In the UK it is estimated that there are over 15,000 people  with Sickle Cell and over 250,000 with Sickle Cell trait (Sickle Cell gene).

Things that can cause sickling of red blood cells include:

Treatments for Sickle Cell

child with a big smile

Blood transfusions

Blood transfusions may be necessary for a number of reasons including preventing strokes, worsening anaemia, improving oxygen delivery to the body and lungs during an acute chest syndrome episode, and to prevent complications before an operation.


Hydroxyurea: A drug shown to improve symptoms by reducing pain episodes and the need for blood transfusions in Sickle Cell.

Bone marrow transplant

Bone marrow transplant: This is currently the only cure for Sickle Cell. Whilst this treatment has been done successfully on many people with Sickle Cell there are many complications. Although the majority will survive a transplant, 1 in 10 will not.  Also finding a match can be difficult.

Gene therapy

Gene therapy: the future cure to replace the defective gene with a normal gene.

Folic acid

Folic acid to help the body make new red blood cells. The sort of anaemia experienced by people with Sickle Cell is known as haemolytic anaemia.  This is not the same as the sort of anaemia caused by lack of iron. The anaemia in Sickle Cell is caused by the haemoglobin S where the red blood cells do not live as long. The body tries to keep up by making more red blood cells but it usually cannot do this and therefore causes anaemia.


Penicillin: Children with Sickle Cell are 600 times more likely to get pneumococcal infection than other children. This is because their spleen does not filter infection properly. The spleen is an important part of the body’s defence against infection.

Healthy diet and hydration

Healthy diet and hydration : Hydration is important because insufficient water in the body can trigger a Sickle Cell crisis. A healthy balanced diet because most of the food intake of someone with Sickle Cell goes towards making new red blood cells.

Voxelotor (Oxbryta)

Voxelotor (Oxbryta). Oxbryta works on haemoglobin S to interfere with the first step of the process that causes red blood cells to sickle (polymerization). Because Oxbryta impacts this very first step, it helps to prevent sickling and haemolysis (the breakdown of red blood cells). Homolysis can lead to anaemia (having too few red blood cells). Oxbryta is for use in adults and children 12 years of age and older. The FDA recently approved this oral drug to improve anaemia in people with Sickle Cell in the USA and is awaiting approval by NICE for use in the UK.

Crizanlizumab (Adakveo)

Crizanlizumab (Adakveo). Crizanlizumab is a monoclonal antibody, a type of protein, that can bind to and inhibit P-selectin. Thereby it can help maintain normal blood flow and prevent a vaso-occlusive crisis. Crizanlizumab is given as an infusion into a vein. A healthcare provider will give this injection. Crizanlizumab must be given slowly, and the infusion can take about 30 minutes to complete. Crizanlizumab is usually given once every 2 to 4 weeks. Crizanlizumab is for use in adults and children at least 16 years old. The FDA recently approved this drug for treatment of Sickle Cell Anaemia and is awaiting approval by NICE for use in the UK.

L-glutamine oral powder (Endari)

L-glutamine oral powder (Endari). Endari works by increasing the amount of glutamine in the blood. The added glutamine is taken up by the defective sickle cells, and when metabolised (broken down) results in the release of antioxidants. These antioxidants lower stress on the sickle cell, help free them up for oxygen delivery to organs and other tissues in the body, and lessen pain and swelling. Endari is for use in adults and children over 5 years old. The FDA recently approved this drug for treatment of sickle cell anaemia in the USA and is awaiting approval by NICE for use in the UK.

Mother and child hugging

Sickle Cell FAQs

Does Sickle Cell only affect black people?

This is not true. Although it is more common in black people, it can occur in any racial group.

Does Sickle Cell affect everyone the same?

No. There are different types of Sickle Cell and so each individual can have very different experiences. Some people may need regular blood transfusions.  Some people may be admitted to hospital regularly as a result of Sickle Cell complications whereas others may not need to be admitted to hospital for years.

Are people with Sickle Cell allowed to go swimming?

Sickle Cell affects people differently. Some people can cope with the strenuous exercise and change in temperature; others may find that this can trigger a pain crisis particularly if the water is cool. If you do decide to go swimming or take a child with Sickle Cell swimming make sure the water and atmosphere around the pool are not cold. Wrap up as soon as you get out of the pool to avoid the skin chilling. Take care to make sure hair is dried quickly as we lose a lot of body heat from our head.

Do people with Sickle Cell live to old age?

Sickle Cell can cause many complications that could cause early death if symptoms are left untreated.  However, people can and do live into adulthood and even old age.

I have Sickle Cell trait. Can I still donate blood and or bone marrow?

Yes, you can still donate blood and be a bone marrow donor.

Why is Sickle Cell pain more common in cold and windy weather?

If the skin cools rapidly  - for example getting into a cold pool and getting out and staying wet  - the chilling of the skin can cause a Sickle Cell crisis.

Does Sickle Cell protect against malaria?

People living in malarial areas of the world that have Sickle Cell trait do build up some partial resistance to malaria, however, once they move away from a malarial area they lose this partial resistance. Those with Sickle Cell conditions react very badly to malaria. It is important that adequate protection is given to those with Sickle Cell conditions travelling to malarial areas because malaria can be fatal in people with Sickle Cell conditions.

Where can I be tested for Sickle Cell?

If you are living in the UK you can request a test at your local Sickle Cell screening centre or at your GP practice. Newborn babies are now tested when they have their heel prick test.

Can you catch Sickle Cell?

Sickle Cell is genetic and cannot be caught. People are born with it.

If Sickle Cell is so common why have I not heard of it before?

Discrimination may impact the level of attention Sickle Cell receives. This is prevalent in funding, research, support, education and development of new treatments.

How do I know if I have Sickle Cell or Sickle Cell trait?

The only way to know if you have Sickle Cell or are a Sickle Cell carrier is by having a blood test to determine your haemoglobin type.

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