Routine operations, blood tests and GP appointments have been delayed or cancelled after a cyber-attack affected computer systems in hospitals and GP surgeries across England and Scotland on Friday.
A number of hospital trusts and GP surgeries are still facing serious issues, following a weekend of disruption.
Below are some of the NHS services with ongoing IT issues:
Barts Health, the largest NHS trust in the country, operating five hospitals in London, is still being affected by IT issues. Some surgeries and outpatient appointments will be cancelled at The Royal London, Whipps Cross and St Bartholemew's hospitals, but renal dialysis services will continue as normal. The trust's hospitals will be running a reduced service on Monday and Tuesday. All of the hospitals remain open for emergency care.
Basingstoke and North Hampshire Hospital has a reduced x-ray service after damage caused by Friday's attack. It said patients referred by GPs for x-rays should attend the Andover War Memorial Hospital, the Royal Hampshire County Hospital or the Alton Community Hospital instead. Emergency services from Basingstoke will continue as usual.
The George Eliot Hospital in Nuneaton said patients attending routine appointments may experience delays due to issues with the IT system. A spokesperson added that the accident and emergency department remained safe.
North Cumbria University Hospitals NHS Trust is advising patients that GP appointments may be delayed through the course of Monday as IT systems are turned back on after the bug. The trust has also asked patients with non-urgent appointments to rearrange consultations.
The Royal Berkshire Hospital in Reading is running services as normal, but patients have been told not to call the hospital unless it is urgent, as the phone lines have been impacted by the cyber-attack. Patients will be contacted directly, should the hospital need to reschedule.
Hospitals and GP surgeries in Blackpool, Fylde and Wyre are still experiencing IT problems. Patients have been advised that planned care will go ahead but they may have to wait longer. Blackpool Teaching Hospitals Trust said patients should only attend A&E in life-threatening or urgent cases.
Broomfield Hospital in Chelmsford, the main site for Mid Essex NHS Trust, cancelled all non-urgent blood tests on Monday, after issues caused by the cyber-attack. Some clinics and appointments have been rescheduled.
Colchester General Hospital in Essex cancelled a number of operations on Monday because of issues with computer systems in its pathology department. All outpatient appointments from its hospital in Harwich were cancelled.
James Paget Hospital in Norfolk, say they are delivering care as normal, though some appointments have been postponed and delays are occurring.
Southport and Ormskirk Hospital said difficulties with its IT system are ongoing. All routine surgeries, endoscopy appointments, and routine MRI and CT scans, have been cancelled on Monday and Tuesday. Dialysis patients have been told to attend as usual. Antenatal units, pregnancy assessment, gynaecology and sexual health clinics are running as normal.
GP surgeries across Lincolnshire have been severely affected by last week's cyber-attack. Consequently all computers across the county have been shut down. Doctors do not have access to patients' files, prescriptions or blood test results. United Lincolnshire Hospitals NHS Trust, which operates four hospitals in the county, has warned patients that outpatient appointments, routine operations and diagnostic tests have all been cancelled on Monday.
York Teaching Hospital NHS Trust has warned that bone scan appointments at Scarborough Hospital have been cancelled. All outpatient clinics at Selby Hospital - except for blood tests and physiotherapy appointments - have been cancelled. Physiotherapy appointments at Clifton Chapel in York have also been cancelled.
Northumbria Healthcare NHS Trust, which operates 11 sites and hospitals in the northeast region, has postponed all CT and MRI scans on Monday as a result of the cyber-attack.
Lancashire Teaching Hospitals NHS Trust, which operates the Royal Preston Hospital, has cancelled the majority of planned procedures and operations on Monday. The majority of outpatient clinics will go ahead as planned.
Staffordshire and Stoke-on-Trent Partnership NHS Trust, which runs the social care services and the Haywood Hospital in Stoke, said it had cancelled all outpatient and day cases at its site. It said staff would rearrange patient appointments as soon as possible.
East and North Hertfordshire NHS Trust has said it is not running any non-urgent blood tests at the Lister, the New QEII, and Hertford County hospitals. The trust's diabetic eye screening service is also not running.