Urgent NHS appeal for O-type blood donors amid national shortage

Alert comes as hospitals in England asked to restrict use of O-type blood as aftershocks of June cyber-attack continue

The NHS has made an urgent appeal for more blood donors after a national alert over supplies dropping to an unprecedentedly low" level.

O-negative blood - known as the universal blood type - is safe for all patients requiring blood transfusions. Making up about 16% of all hospital orders, it is used in emergencies or when a patient's blood type is unknown.