NHS Lanarkshire has stated that these measures are required following "unprecedented pressures" and in order to "free up staff and beds for urgent care".
Most non-urgent operations which are currently scheduled to take place within the next few weeks are expected to be postponed to a later date.
Dr John Keaney, NHS Lanarkshire acute medical director, said: “The sustained pressure we are seeing across our three acute hospitals is showing no signs of easing and our staff are struggling to cope.
"We are facing relentless pressures, bed shortages and staff shortages due to sickness, stress and self-isolation.
"Unfortunately we are having to postpone the majority of non-urgent procedures and I would like to apologise to those patients affected".
Last Monday, more 700 people were treated at the A&E departments of all three Lanarkshire hospitals and NHS Lanarkshire has asked for all those who may require non-urgent medical attention to consider whether or not they need to attend hospital and to seek advice from NHS24 by calling 111.
Patients will receive a letter, text message, or voice message giving details of any cancelled, postponed, or rescheduled appointments.
Shortly before going to press it emerged that another restriction would come into place after the board announced a change in policy over hospital visiting.
Trudi Marshall, Nurse Director said: “Unfortunately, we have seen a rise in the number of Covid patients in our hospitals, and it is our priority to protect our patients and staff as much as is possible.
"This is why we have made the difficult decision to have one dedicated visitor each day.
“The named person will be able to have close contact with their loved one, such as holding hands.
"This will provide those patients in hospital with the vital support they need from family, carers or friends.
“Visiting will continue to be by appointment only and visitors should contact the ward to arrange a time.”