With just 46 Covid-19 beds to spare, NHS Lanarkshire officials warned that the number of patients with the virus is expected to double in the next week, an increase of almost 300.
The Medical Director of Ayrshire and Arran said the current crisis is putting “great strain on every aspect of the system”.
It comes as health boards across the country warn of stretched capacity, and the Royal College of Emergency Medicine said Scotland is facing a “crisis like never before” under winter pressures, with the worst “still to come”.
First Minister Nicola Sturgeon announced on Tuesday that 1,717 patients are being treated in hospital with Covid-19, 133 of them in intensive care.
A further 54 deaths within 28 days of a positive Covid-19 test were reported, taking the figure above 5,000 for the first time.
Some outpatient appointments in NHS Lanarkshire will also be cancelled, while clinically urgent and priority procedures will continue.
The measure will come into effect from Wednesday, and last for four weeks initially.
The health board will focus on Covid-19 inpatients and emergency care, as well as some urgent cancer care.
NHS Ayrshire and Arran has suspended elective surgeries until further notice.
“This phase of the pandemic is having the greatest impact on our communities in terms of positive cases, numbers admitted to hospital and sadly deaths. This is placing great strain on every aspect of the system,” said Medical Director Dr Crawford McGuffie.
It comes as Nicola Sturgeon announced 1,875 new cases of Covid-19 in Scotland on Tuesday, with 54 new deaths reported and 133 people in intensive care with Covid-19.
Some 1,717 people are in hospital with Covid-19, a figure higher than the peak of the first wave.
Covid-19 hospital capacity has been at breaking point for several days in areas of Scotland, with NHS Lanarkshire and NHS Ayrshire and Arran already having breached their bed limits for Covid patients – a metric which can fluctuate.
NHS Lanarkshire currently has 288 Covid-19 patients in its hospitals, with 16 in intensive care.
But health officials warned this figure is expected to double.
Judith Park, director of acute services for NHS Lanarkshire, said: “The safety of our patients is always our top priority. Winter is always a difficult time for the NHS. However, the current pandemic has had an additional impact on our services.
“The hospitals are full and the numbers of Covid-19 admissions are increasing. As such, there are only 46 beds currently available to new patients.
“We currently have nearly 300 patients being treated for Covid-19 in our hospitals, with additional patients currently waiting on test results. However, we are anticipating this number to double within a week putting our hospitals under severe pressure.”
The Royal College of Surgeons said the move to cancel operations was to be expected given the situation in Scottish hospitals.
"While it is disappointing to see the cancellation of elective procedures, it is unsurprising given the situation we are currently facing,” said Professor Michael Griffin, president of the college.
"The NHS is under a huge amount of pressure at the moment, and unfortunately, some areas are now reaching the point where they have no choice but to postpone all but the most urgent operations.”