Ms Sturgeon said she was "far from convinced" measures could be eased on the next review date of May 7.
The Scottish First Minister told ITV's Peston: "People talk about lifting the lockdown, that is not going to be a flick of the switch moment - we're going to have to be very careful, very slow, very gradual.
"I'm far from convinced at this stage that when we get to the next review point on the 7th of May we'll be in a position to lift any of these measures right now, because the margins of manoeuvre that we're operating in right now are very, very, very tight and narrow."
Ms Sturgeon was speaking amid claims the Government had shifted its language on one of the key five tests it has outlined for getting to a position where the lockdown can be eased.
After stating that adjustments to present rules should not risk a second peak of infections, the Government said changes should avoid a second peak that overwhelms the NHS.
Asked whether the Government had shifted its language, Ms Sturgeon said: "It is necessary to have as an objective not overwhelming the NHS, but not sufficient to have that as your only objective.
"Because, if you take the situation in Scotland right now, and this will be similar across the UK, we have the numbers of people in intensive care around just over 100, but we've got a capacity in intensive care of nearly 600.
"So, if your only objective was not overwhelming the NHS I could say to you, well we could afford to have the numbers of people in intensive care quadrupling, and we still wouldn't be overwhelming the NHS."
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