People suffering from the disease, also known as chronic fatigue syndrome, are currently allowed to donate blood if they are in remission.
But from November 1 ME patients – who can be prone to relapses – will be prevented from doing so as a precaution to preserve their health.
It is not known what causes ME, but the condition has been linked to a virus known as XMRV, which American scientists found in two thirds of ME patients compared with just one in 25 of the population at large.
The NHS said the ban is “a precaution to protect the donor’s safety by ensuring their condition is not made worse by donating blood”.
Similar measures are in place for other conditions where relapses are common or where the cause is not known, such as Parkinson’s disease and multiple sclerosis.
The move follows a decision by the American Association of Blood Banks in June this year to put a temporary block on blood donations from patients with ME.
Dr Charles Shepherd, medical adviser to the ME Association, told the BBC: “In the current state of uncertainty about a possible viral link a ban is a perfectly sensible measure to take in case it is caused by a retrovirus.
“Although people with ME often want to donate blood, they make up a small number of the many thousands of donations the NHS receives each year.”
Telegraph UK