“Treat the word orthopaedic as a description of a firm spring build, not a medical promise, and choose between medium-firm and firm by your weight and the way you sleep.”
An orthopaedic mattress, in UK shops, is usually a firm or extra-firm pocket-sprung mattress sold for back and joint support, but the word has no agreed definition. Bed Advice UK, the consumer site of the National Bed Federation, says terms like “orthopaedic” vary by brand and “don’t follow any universal firmness standard”. So judge an ortho mattress on four things you can check yourself, which are its firmness against your weight, how the springs are built, whether it can be turned, and the price in your size.
What the orthopaedic label means
The Advertising Standards Authority treats orthopaedic wording as a health claim. In a ruling published on 18 December 2024, it upheld a complaint against Origin Mattress over website claims including “Orthopaedic Back Support” and set out the proof it expects: “We therefore expected to see robust documentary evidence substantiating those various claims, consisting of clinical trials conducted on people.” Origin had sent no evidence at all.
Medium-firm or firm
Firmer is not automatically better. The strongest evidence is a randomised, double-blind trial published in The Lancet in 2003 (Kovacs et al.), which gave 313 adults with chronic low back pain either a firm mattress, rated 2.3 on the European H(s) scale where 1 is the firmest and 10 the softest, or a medium-firm one rated 5.6. After 90 days the medium-firm group had better outcomes for pain in bed (odds ratio 2.36) and for disability (2.10). A 2015 systematic review of 24 controlled trials in Sleep Health (Radwan et al.) found that a mattress described as medium-firm and self-adjusted (custom inflated) was optimal for sleep comfort, sleep quality and spinal alignment.
That is why a medium-firm hybrid tops this ranking. Firm still has its place. Silentnight describes its Firm rating as highly supportive “for sleepers with a heavier build”, and OTTY recommends its Extra Firm Hybrid for people over 15 stone (95kg). If you are lighter and sleep on your side, a firm ortho mattress is more likely to press on your shoulder and hip, so look at our side sleeper and soft mattress rankings instead. Our best mattresses for heavy people compare firm picks by weight rating, and best mattresses for back pain looks at pain by sleeping position.
Read spring counts with care
The number in an ortho mattress’s name rarely applies to every size. John Lewis lists the spring count per size for its own Ortho Pocket Collection 1400, and it is 819 in a single against 1,435 in a king. Some headline counts also add two kinds of spring together. REM-Fit’s 4,000 is 2,000 pocket springs plus 2,000 mini springs, and the Simba Hybrid Pro’s up to 4,800 combines up to 3,800 microsprings with up to 1,000 steel springs. Tension and zoning tell you more about support than the total. Hypnos sells the Orthos Support 7 in Firm or Extra Firm tension, Silentnight zones its 1,400 Mirapocket springs, and Sealy puts a Powerpack in the centre of the Grasmoor to add support under the lower back. Our Hypnos and Silentnight range comparisons set these ortho models against each maker’s other mattresses.
Turnable or one-sided
The Silentnight, Hypnos, Sealy and OTTY are double-sided. Turning a mattress as well as rotating it spreads wear over two sleep surfaces, and Sealy’s guarantee terms require double-sided mattresses to be turned and rotated head to toe. The OTTY’s two sides differ (9/10 and 10/10), so flipping it changes the feel rather than just refreshing it. The one-sided hybrids from Emma, Simba and REM-Fit only need rotating, which suits anyone who cannot lift a heavy king. Whichever you choose, Bed Advice UK says sleep experts recommend replacing a mattress every seven years, after more than 20,000 hours of use.
Specifications below come from each maker’s or retailer’s UK product page, and the orthopaedic fit score is explained in our methodology.
Demand for ortho mattresses is spread across sizes, so here is each pick in the four main UK sizes at the time of writing (prices checked 28 September 2026).
