Scottish Labour leader Anas Sarwar also pressed the First Minister on the ongoing underperformance of NHS Scotland, stating that last year the SNP promised normal service would soon resume.
The SNP leader was also criticised for failing to get business support funds connected to Covid-19 restrictions out to businesses before Christmas.
However, Mr Sarwar claimed one of Scotland’s biggest health boards was now operating an “emergency-only service”, with NHS Lanarkshire stating its GPs would only focus on the most serious cases.
Ms Sturgeon emphasised the impact of the pandemic on the NHS, saying the suspension of services would not last any longer than necessary.
On Wednesday, the health board announced it had asked all GPs to focus on the most urgent and time-critical care as part of a “managed suspension of services”.
The health board declared a black alert in October last year as hospitals came under pressure.
Mr Sarwar said problems with NHS capacity predate the pandemic and were getting “worse, not better”.
Ms Sturgeon disagreed, saying coronavirus has dealt the health service “two significant additional blows” in the past ten months.
She said NHS Lanarkshire was in level two of its GP escalation framework for the next four weeks, which is not the most serious level.
The First Minister said: “That ensures that given the staff absences that are being experienced right now, we can continue to focus on the patients who most need care
“None of us want to be in this position, we hope we’ll be out of this position sooner rather than later.”
Scottish Labour central Scotland MSP Monica Lennon also raised NHS Lanarkshire during First Ministers’ Questions, saying people in the region were “very afraid of becoming sick”.
She said: “What am I supposed to tell constituents in Lanarkshire who are reaching for the Samaritans Scotland phone number because they can’t get through to GP surgeries?”
The First Minister said she understood that for people in Lanarkshire and the wider public, this “is a really anxious time because of the ongoing challenges of Covid and the impact that is having on the National Health Service”.
She said: “This is a short-term measure. Nobody wants or will allow it to be in place for longer than necessary.”
Scottish Conservative leader Douglas Ross said the Government had not done enough to ensure businesses received additional help over Christmas.
He said: “The process is going at a snail’s pace. One business group said yesterday that ‘not a single penny of the funding we were promised before Christmas has reached businesses’.
“The SNP are quick to demand more funding from the UK Government, but incredibly slow to get it out the door to businesses, many of whom are on the brink and simply can’t afford to wait a month.”
The First Minister rejected the characterisation of the situation, stating the additional money being sent to businesses was more than what they would receive south of the border.
She also accused Mr Ross of opposing the Government on every issue, adding “the country would be in a sorry state” if the Scottish Tory leader had been in her position.