Support the curve you have without pressing it flat
A giving surface over a supportive core is where I'd start, because you need cushioning at the points that touch the mattress without sinking unevenly through it. Very firm can feel like lying on a paving slab when your upper back and shoulder blades touch first. The lower back may then feel unsupported. Choosing the hardest option is no achievement, even if the showroom pitch makes it sound like one.
At the other extreme, a very soft mattress can let your pelvis sink farther than your shoulders, or your shoulders farther than your pelvis. You're looking for enough give to settle comfortably, with steady support underneath. Pressing the surface with your hand tells you very little about that balance: your whole body puts a different load on it. Give yourself permission to lie down properly, shoes and showroom awkwardness dealt with, before you judge the feel.
The NHS describes kyphosis as a curve in the spine that makes the top of your back look hunched or rounded.1 It names three types: postural kyphosis, the most common type, which often affects teenagers; Scheuermann's kyphosis; and congenital kyphosis, which is rare. That is a reason to get the shape assessed if you haven't already, rather than choose a mattress based on how your back looks.
For firmness, start with how much you compress a mattress, then account for how you sleep. Medium-firm is a useful first option for many people, but a lighter side sleeper may barely sink into something a heavier back sleeper finds comfortable. Ignore matching firmness labels across brands: each maker uses its own scale.
These are my practical shopping starting points, not clinical weight thresholds or prescriptions for kyphosis. Your comfort and your physiotherapist's advice come first.
| Your build or position | What to try | What to notice |
|---|
| Under about 9 stone | A softer surface, especially on your side | Whether your shoulder sinks enough without pressure building against it |
| About 9 to 18 stone | Medium-firm support with a giving comfort layer | Whether your upper back feels cushioned and your pelvis stays supported |
| Over about 18 stone | Firmer support with substantial cushioning above it | Whether you sink through the comfort layer and feel the harder support beneath |
| Mostly on your side | A little more surface give than you would choose for back sleeping | Whether your shoulder can settle without your neck bending upwards |
Match your pillow to your head's position
The pillow is the cheaper experiment when your head tilts back or your neck feels bent, so check that before replacing a sound mattress. It's easy to spend ages choosing a bed and then put the same flattened pillow back on it. On your back, a rounded upper back can leave your head tilted backwards on a low pillow. My practical view is to try a higher or shaped pillow that fills the gap behind your head and neck without pushing your chin towards your chest.
The useful height depends on where your upper back settles into the mattress. A pillow that feels right on one surface can feel too high or too low on another. Try the pillow and mattress together, and notice whether you can rest your head comfortably without holding it in place. Our back-sleeper mattress guide covers the broader support choices for that position.
On your side, your shoulder needs room to sink and the pillow needs to fill the remaining gap between your head and the mattress. A very firm surface can keep the shoulder high enough that your neck bends upwards. The side-sleeper guide covers that balance of cushioning and support; the neck-pain guide gives you more on matching the pillow to your position.
Front sleeping is the position I would steer you away from because you have to turn your head to breathe and can hold your neck twisted for a long time. Back or side is the practical place to begin, provided you can rest comfortably there. There's no prize for maintaining a picture-perfect position while you're awake half the night. If your physiotherapist has recommended a position for you, follow that advice ahead of mine.
Choose for comfort while your GP manages the condition
The evidence for particular mattresses and kyphosis is thin, so I use straightforward comfort checks: no sag beneath you, no concentrated pressure against your upper back, and enough responsiveness to turn easily. A complicated mattress name adds nothing to those checks. You also need a pillow that fits where your head actually rests once you've settled.
Easy turning matters when you're choosing between a springy surface and a deeply enveloping one. Some people enjoy sinking into memory foam; others feel as though they're moving through quicksand whenever they change position. Try turning both ways while you're lying down. To my mind, latex or springy foam over pocket springs is a sensible place to start if you dislike that held-in feeling.
For a teenager, the NHS describes postural kyphosis, usually caused by bad posture, as the most common type and says it often affects teenagers. The NHS also says physiotherapy may help improve posture. Arrange a GP appointment if you think your child might have kyphosis, so you can get advice about their particular situation.
I think a growing child should have a proper new mattress with support and cushioning suited to their size. The spare-room hand-me-down can remain in the spare room. Let your teenager try the mattress in the positions they actually use, and take their account of pressure or difficulty turning seriously. Buying something harder than they find comfortable won't make it a better choice.
Test the whole bed before you commit
Lie on your back and your side for ten minutes each with a pillow similar to your own, because a quick sit on the edge won't tell you how your upper back settles. Showroom politeness is a bloody expensive reason to rush. Notice the contact beneath your shoulder blades and whether your lower back feels supported; on your side, notice whether your shoulder has enough room to sink. Stop if a position increases discomfort, and follow any individual restrictions your clinician has given you.
A hybrid, with pocket springs beneath a substantial comfort layer, is the construction I'd try first. The springs provide the supportive core; latex or springy foam gives you cushioning with an easier change of position. Memory foam is an option if you enjoy a closer, slower sink, but I would steer hot sleepers towards a more breathable construction. Don't let an elaborate cooling name substitute for checking the fillings and considering how warm you already sleep.
There is a cheaper experiment if your existing mattress is level and supportive but too hard at the surface: a soft topper. It adds cushioning where your upper back and shoulders meet the bed. Check the mattress and base for a dip first, because a topper follows a sag underneath it. Buying a softer layer for an uneven bed leaves you with the same uneven support.
At home, allow for some adjustment during the first fortnight. The first evening has enough novelty about it without declaring a lifelong commitment before breakfast. Keep a short note of where you feel pressure, whether you can turn comfortably and how your pillow fits. Compare several nights, but don't force yourself through increasing pain in the hope that adaptation will fix it.
Read the returns terms before ordering, including any minimum-use requirement and the collection arrangements. Keep a copy with your order confirmation so you can act within the relevant deadline. If you think you or your child has kyphosis, contact your GP; if you already have a diagnosis and your discomfort is persisting or changing, ask your GP or physiotherapist for advice.
Avoid buying hardness as a posture fix
Skip anything that presses against your upper back or leaves you sinking unevenly, however persuasive the display looks. A serious-looking label is still a label. These are the choices I would rule out before paying:
- A very firm mattress bought to "straighten" your back. It can press against the rounded upper back. Hardness alone is a poor basis for choosing comfort.
- A flat pillow that leaves your head tilted backwards. For back sleeping, try enough height or shaping to fill the gap behind your head and neck.
- A soft, sagging mattress. Your shoulders and pelvis can drop unevenly, and extra cushioning won't remove the dip.
- Sleeping on your front. Your neck stays turned; discuss a comfortable back or side position with your physiotherapist if changing position is difficult.
- Buying a mattress as posture treatment. The NHS names physiotherapy as help that may improve posture and advises starting with a GP.
Keep the purchase focused on the physical fit, even if the sales pitch gets grander than that. You need to be able to rest your upper back comfortably and change position without struggling; use those checks to rule a mattress out.
Kyphosis is a GP matter first
A mattress does not change a curve in the spine. NHS guidance on kyphosis says to see a GP if you think you or your child might have kyphosis. The NHS describes kyphosis as a curve in the spine that makes the top of your back look hunched or rounded, names postural kyphosis (usually caused by bad posture, often affecting teenagers) as the most common type, and says physiotherapy may help improve posture. Follow your GP's and physiotherapist's advice before anything on this page.
