Is bed rest bad for a bad back? The trials say stay moving

When a back "goes", the instinct — and for much of the twentieth century the medical advice — was to lie down and wait it out. Two Cochrane reviews of the randomised evidence reach the opposite conclusion: for ordinary acute low back pain, resting in bed is, if anything, slightly worse than staying on your feet [s1][s2].

The larger review pooled eleven trials covering 1,963 patients [s1]. It found high-quality evidence that people with acute low back pain who are advised to rest in bed end up with a little more pain — a standardised mean difference of 0.22 (95% confidence interval 0.02 to 0.41) — and a little less functional recovery, SMD 0.29 (95% CI 0.05 to 0.45), than those advised to stay active [s1]. A separate Cochrane review built around that same advice comparison found the same thing: across two trials of 401 patients, staying active produced small improvements in pain relief (SMD 0.22, 95% CI 0.02 to 0.41) and function (SMD 0.29, 95% CI 0.09 to 0.49) [s2].

These are modest effects, and standardised units are not something a patient feels directly. The point is the direction. Neither review found any measurable advantage to bed rest, and both found a small penalty for it.

Sciatica is a flatter picture

For sciatica — pain that radiates down the leg when a nerve root is irritated — the evidence is less one-sided. Both reviews found little or no difference between resting and staying active, with a pain SMD of −0.03 (95% CI −0.24 to 0.18) and a functional-status SMD of 0.19 (95% CI −0.02 to 0.41) [s1][s2]. Resting does not help sciatica, but the case against it is weaker than for a plain aching back.

Longer rest buys nothing

If someone does end up lying down, the length of the spell does not seem to matter. The larger review compared shorter and longer rest directly and found moderate-quality evidence of little or no difference in pain intensity or functional status between two to three days and seven days of bed rest [s1]. There is no version of the trial evidence in which a longer lie-down comes out ahead.

What "stay active" actually means

Neither review is an instruction to push through pain or to start a workout. The trials compared advice — to rest versus to keep doing ordinary daily activities within the limits of the pain — not specific exercise programmes. When the reviews looked at more structured options, the differences shrank further: low-quality evidence suggested little or no difference between advice to stay active, exercises, or physiotherapy for acute low back pain [s2]. So the honest reading is narrow. Staying gently mobile beats going to bed; beyond that, the evidence does not crown a winner.

When it is not "wait and see"

Most acute back pain eases over days to a few weeks regardless of what a person does, which is part of why bed rest ever looked effective — people recover anyway. But some symptoms are not candidates for watchful waiting. New or worsening weakness in a leg, numbness around the groin, inner thighs or buttocks, or any loss of bladder or bowel control can signal serious nerve compression and warrant urgent medical assessment rather than rest. Back pain with fever, unexplained weight loss, or pain that is severe at night and unrelieved by position change also deserves prompt review.

The caveats

The evidence here is settled but old: the reviews date from 2004 and 2010, and the trials behind them are older still [s1][s2]. That is less of a weakness than it sounds — the finding has not been overturned, and it underpins current back-pain guidance worldwide — but it means there is little modern trial activity refining the question, because the field long ago moved on from bed rest as a treatment. The effect sizes are also small and measured on standardised scales, so no one should expect staying active to abolish the pain. It will not. What it will do, on the best available evidence, is get someone back to normal function slightly faster than the mattress will [s1][s2].

The practical upshot is unglamorous. For a typical bout of low back pain, the trial record favours keeping to light, ordinary movement over a stint in bed — and if the pain comes with leg weakness or bladder changes, it favours a doctor over either.