NHS waiting lists for diagnostic tests have risen 11.7 per cent in the past year, new figures show.

Long waits for tests, including MRI scans, CT scans, ultrasounds, endoscopies, and heart investigations, can delay treatment for serious conditions such as cancer and heart disease.

At the end of January 2026, nearly 1.8 million patients were waiting for a diagnostic test, marking an increase of almost 190,000 from January 2025.

NHS rules state that no more than one per cent of patients should wait longer than six weeks. 

Yet the latest data shows around a quarter of patients - roughly 447,000 - are waiting six weeks or more for one of the 15 key diagnostic tests. 

Compared with the same period last year, the number waiting six weeks or more increased by roughly 84,000 (2.3 per cent).

The pressure on diagnostic services is part of a wider strain on the NHS, with demand for mental health services also reaching record levels. 

The number of people in contact with NHS mental health services rose to over 2.2 million in January, up from 2.04 million in January 2025 and 1.39 million in January 2020.

Despite these pressures, the overall referral to treatment waiting list fell to 7.25 million, its lowest level in almost three years - 44,000 fewer than the previous month and 180,000 fewer than in January 2025.

NHS England said this reduction came despite the NHS facing its busiest winter on record, with more than 9 million A&E attendances and record ambulance demand. 

NHS leaders said the figures show progress in tackling backlogs, while acknowledging there is still 'far more to do' to reduce waiting times across the health service.

For patients, delays in diagnostic tests and treatment can mean months of uncertainty and anxiety while waiting for a diagnosis.

Brett Hill, Head of Health and Protection at independent financial consultancy Broadstone, said: 'While the referral to treatment waiting list may be at its lowest level in three years, this positive trend masks a troubling reality. 

'More people are waiting for diagnostic tests - effectively on a waiting list to get on the waiting list - while mental health services are in record demand. 

'Early detection through preventative health services is increasingly important to prevent conditions from becoming chronic.'

The figures follow previous data showing the NHS is failing key cancer targets, with some patients waiting more than 104 days from referral to treatment. 

Almost all trusts failed to meet the longstanding 62-day standard, under which 85 per cent of patients should start treatment, with the worst-performing hospitals treating fewer than half of patients on time.

Delays in diagnostic tests can exacerbate these long waits for cancer treatment, reducing survival chances, making some treatments less effective, and increasing patient anxiety. 

The 85 per cent target for treatment within 62 days has not been met nationally since 2014.

NHS national medical director Professor Meghana Pandit said: 'The NHS was ready to tackle winter head on this year, which is why, despite record-breaking demand, staff have delivered the shortest winter waiting times for four years while waiting lists have continued to fall.

'This is proof that the NHS is starting to turn a corner for patients - but we know the job is far from done.

'For too long, too many patients have faced the indignity of being treated in hospital corridors. 

'That's why we're taking a zero-tolerance approach, with hospital leaders out on the wards ensuring patients are treated with the dignity they deserve.

'I also want to thank the public for their role in supporting the NHS this winter - these figures show the huge impact of the public getting vital winter jabs.'