Demand for blood needed to treat rare disorders such as sickle cell has soared by more than 130% in 10 years, forcing the NHS to ask for more donors to come forward.

Requests for haemoglobin S (HbS)-negative blood, the type most used in blood transfusions for sickle cell anaemia patients, stood at 82,181 units in 2015. But last year, more than 191,000 units were needed, a 132% increase.

HbS is a type of haemoglobin commonly found in people with sickle cell trait and sickle cell disorder. It gives red blood cells a crescent or ‘sickle’ shape, reducing the flexibility of the cells in blood vessels.

For transfusions, patients with sickle cell should receive blood that does not contain HbS. This helps ensure the transfused blood works normally and does not worsen their condition.

The increasing need for HbS-negative blood reflects the growing demand for transfusion programmes for people living with sickle cell disorder, a condition which affects 17,000 people across England, primarily from African and Caribbean backgrounds.

The NHS Blood and Transplant service (NHSBT) has highlighted the soaring demand from sickle cell disease patients and has made urgent appeals for Black people to donate. It has about 775,000 blood donors overall, about 21,500 of them of Black or mixed Black ethnicity.

John James, chief executive of the Sickle Cell Society, said: “These figures show an urgent need for more blood donors, especially from Black and brown heritage communities. The blood types most commonly needed for sickle cell patients are more prevalent in people of Black heritage, who remain under-represented in the donor pool.

“That’s why, working in partnership with NHS Blood and Transplant, we’ve developed our Give Blood, Spread Love programme to increase the number of Black-heritage donors. Giving blood is a simple act that can save or improve up to three lives, and for people with sickle cell it can be life-saving.”

The increase in demand has been attributed to a range of factors, including an ageing population, more use of transfusions where all of a patient’s blood is replaced and an increase in numbers from areas where sickle cell is more common. Many sickle cell patients develop antibodies that mean they require very closely matched blood.

Requests made to NHSBT for rare blood for patients with sickle cell disorder increased by 191% from 2023 to 2025.

Chiara Vendramin of NHSBT said: “Beyond the HbS-negative requirement, there are many other blood group types to consider. Patients can develop antibodies over time, which makes it harder to find compatible blood and can delay treatment.

“People from similar ethnic backgrounds are more likely to share blood types. This is why increasing the number of donors from Black-heritage communities is especially important. While Black-heritage donors’ numbers have greatly increased, there is still an urgent need for more.”

A NHSBT spokesperson said: “The best matched blood will often come from someone of the same ethnic background. While the number of donors of Black-heritage communities continues to increase, there is an urgent need for more, especially to help people with sickle cell.

“We need donors with well-known blood types but also the rare blood types more prevalent in the Black community.”