A record number of people are waiting for diagnostic tests on the NHS, triggering fears that delays in accessing CT and MRI scans can endanger patients' health. A total of 1.92 million patients in England are waiting to have a test to diagnose their illness, such as an ultrasound scan, hearing assessment, bone scan, or various cancer tests.
Demand for tests is outstripping the NHS's ability to meet it, and one in five of those on the waiting list – more than 400,000 people – are having to wait longer than the supposed six-week maximum, a new analysis of diagnostic services in England has found.
The rise in the waiting list for diagnostic tests contrasts sharply with the NHS's recent success in cutting the backlog for planned hospital care to 7.1 million, which was 500,000 fewer than in July 2025.
Key findings from the report
A report by health technology firm Magentus reveals that the diagnostic waiting list has grown by 500,000 since 2022, is 83% higher than before the Covid pandemic, and on current trends will hit 2 million in March 2027.
It also found that people living in parts of England with the longest waiting lists face unusually long delays to get a cancer diagnosis or access treatment for heart problems. For example, integrated care board areas with the highest proportion of people waiting more than six weeks for a test are almost six times more likely to not get diagnosed with cancer within the NHS's 28-day target.
Concerns for patient health
The Patients Association voiced deep unease at the situation and warned that patients' health can deteriorate while they are waiting to have the diagnostic test needed to kickstart their treatment.
Rachel Power, its chief executive, said: "A diagnostic test is not the end of a patient's journey – it is the beginning. Without it, treatment cannot start, conditions deteriorate, and what might have been caught early becomes something far harder to treat."
"When more than one in five patients is waiting beyond the NHS's own six-week maximum, and median waiting times have risen by more than half since before the pandemic, that is deeply concerning for patients' health. Every week of delay is a week a condition can worsen, a patient's ability to live day-to-day can diminish, and their anxiety about what is wrong can grow," she added.
NHS struggling to meet demand
Marlen Suller, Magentus's managing director for clinical diagnostics, said the NHS is unable to cope with the rising demand for diagnostics driven by the ageing population, the growing number of people living with long-term health conditions, and the push for earlier diagnosis of disease.
The 1.92 million people on the waiting list in March included large numbers waiting for an ultrasound scan (674,100), MRI scan (394,913), or CT scan (207,524). The list is growing even though the NHS is carrying out record numbers of tests and scans – 2.61 million that month alone.
Professor Erika Denton, a radiology expert at the Norfolk and Norwich NHS trust, said: "It can be difficult to see patients waiting for a test to explain their symptoms, knowing the stress and anxiety that can create for them. A test result can bring the reassurance of an all-clear or expedite the patient's treatment. It is also frustrating for staff, who are working incredibly hard every day to meet rising demand, yet continue to see waiting lists increase."
Suller urged NHS bosses to overhaul diagnostic services, making better use of existing capacity, testing patients faster, giving them clearer information, and using financial incentives to drive improvement.
NHS England did not respond directly to the findings. A spokesperson said: "Latest figures show that the NHS delivered more tests, checks and scans over the last financial year than at any point in its history with 29.9 million diagnostic procedures delivered from 170 community diagnostic centres, which provide important diagnostic tests nearer to people's homes. We are determined to keep up progress in bringing waiting times down and that's why we're making it easier to access diagnostic tests with new, expanded or enhanced community diagnostic centres available to patients across England."
