Health officials have launched an urgent plea for 40,000 black people to donate blood.
NHS Blood and Transplant (NHSBT) said that more donors were needed to meet growing demand for a special subtype of blood which is more common in black people.
The health authority said that between 2014 and 2016 there was a 75% increase in the amount of the subtype called Ro blood issued to hospitals in England.
A high proportion of this blood is used to treat sickle cell disease - a condition which is particularly common in people of African or Caribbean descent.
People with sickle cell disease have abnormal red blood cells which do not move around blood vessels easily and have a reduced capacity of carrying oxygen around the body.
The condition, which affects around 15,000 people in the UK, can be extremely painful and cause life-threatening infections and other complications such as stroke or loss of vision.
Blood transfusions can help prevent or relieve these symptoms.
To get the best treatment patients need blood which is closely matched - which is most likely to come from someone of the same ethnicity, but NHSBT said just 1% of people who give blood in England are black.
To mark National Blood Week, NHSBT has launched a new campaign - #ImThere - to try to encourage more donors to register and donate.
Mike Stredder, director of blood donation, NHS Blood and Transplant, said: "We need to ensure that we have the right mix of donors and blood types, to help meet the needs of all patients who need life-saving treatment, especially those with conditions like sickle cell disease who require blood which is more closely matched than by group alone.
"In recent weeks, we have been overwhelmed by the numbers of people stepping forward and wanting to donate and show their support for those affected by recent tragic events.
"Thankfully, due to the loyalty of our regular donors, our emergency stocks have proven to be strong and sufficient, but we still need to ensure that we can be there every day, for every patient who needs us."