Tens of thousands of patients were waiting for routine treatment at Royal Cornwall Hospitals in June, figures show.
A think tank has warned the NHS is under significant pressure amid a fresh round of strikes.
NHS England figures show 48,203 patients were waiting for non-urgent elective operations or treatment at Royal Cornwall Hospitals NHS Trust at the end of June – down from 48,732 in May, but an increase on 41,983 in June 2022.
Of those, 3,064 (6%) had been waiting for longer than a year.
The median waiting time from referral at an NHS Trust to treatment at Royal Cornwall Hospitals was 14 weeks at the end of June – the same as in May.
Nationally, 7.6 million people were waiting to start treatment at the end of June.
Junior doctors are set to stage their fifth strike in the dispute on Friday August 10, walking out for four days from 7am. Consultants will strike for two days from August 24, and have threatened to walk out for a further 48 hours on September 19 if the Government continues to “refuse to agree to pay talks”.
Siva Anandaciva, chief analyst at The King’s Fund think tank, said these strikes are an extra burden on an already stretched health service.
“The longer the strikes go on, the less and less likely it is that the Prime Minister will meet his pledge to reduce waiting lists.
“For the sake of patients, it is imperative that all parties get around the table to resolve this issue. This emphasises how staffing issues make or break almost any target set for the service,” he added.
Separate figures show 1.6 million patients in England were waiting for a key diagnostic test in June – the same as in May.
At Royal Cornwall Hospitals, 14,002 patients were waiting for one of 13 standard tests, such as an MRI scan, non-obstetric ultrasound or gastroscopy at this time.
Of them, 5,452 (39%) had been waiting for at least six weeks.
Other figures show cancer patients at Royal Cornwall Hospitals are not being seen quickly enough.
The NHS states 85% of cancer patients urgently referred by a GP should start treatment within 62 days.
But NHS England data shows just 73% of patients urgently referred by the NHS who received cancer treatment at Royal Cornwall Hospitals in June began treatment within two months of their referral.
That was up from 69% in May, but down from 78% in June 2022 last year.
The Royal College of Nursing – a staff body – warned the health service “is falling into a deeper crisis”.
Chief nursing officer Nicola Range said: “A decade of underinvestment in the NHS has led to dire consequences for patients and pushed many nursing staff out of the profession they love and with unrelenting pressure on those who remain.”
Professor Julian Redhead, NHS England's national clinical director for urgent and emergency care, said: “Today’s data is a reminder of the significant pressure on staff with this summer currently on trajectory to be the busiest in NHS history, all while industrial action continues to disrupt services.”
He said despite this, doctors are doing more tests and checks on patients, and have seen record numbers of people suspected to have cancer.
A Department of Health and Social Care spokesperson said: “We are making progress to deliver on our priority to cut waiting lists and ensure people get the care they need quicker.”
“We have virtually eliminated 18-month waits and are taking action to bring down waits of over a year – including reducing the number of people requiring follow-up appointments,” they added.