Best side sleeper mattress: a UK buying guide
The best mattress for a side sleeper is usually medium or medium-soft. It needs to be soft enough on top for your shoulder and hip to sink in, and firm enough underneath that your waist doesn't sag. Memory foam and hybrid mattresses (pocket springs topped with foam) suit most side sleepers. Very firm mattresses and old, dipping ones suit them least. If your mattress is in good shape but feels too hard, a side sleeper topper and a firm pillow of the right height can solve much of the problem for a lot less than a new mattress.
What a side sleeper needs from a mattress
On your side, nearly all your weight goes through two narrow points: the shoulder and the hip. A mattress that won't give at those points pushes them back up. You feel it as a dead arm, a sore hip, or a lot of turning over in the night.
The aim is a straight spine, from the base of your skull down to your tailbone, as if you were standing with good posture and then tipped over sideways. The shoulder and hip have to sink further than the waist for that to happen. That's why a mattress that feels lovely when you lie on your back can feel like a plank once you roll onto your side.
Firmness and body weight
Firmness labels aren't standard between brands, so one company's "medium" can feel like another's "firm". Your weight matters more than the label:
- Lighter sleepers, roughly under 9 stone (about 57 kg), barely press into a firm mattress and usually do better on medium-soft.
- Sleepers of average weight usually suit medium.
- Heavier sleepers, roughly over 16 stone (about 100 kg), sink further. Medium-firm with a deep comfort layer stops the hips bottoming out.
Depth of the comfort layer
The top layer is where your shoulder sinks. A thin layer over firm springs or dense foam gives very little room, so check how deep the comfort layer is as well as the overall firmness rating. If you share the bed, look for good motion isolation too. Side sleepers tend to shift between left and right during the night, and pocket springs and foam pass on less movement than open coils.
Mattress types compared for side sleeping
| Type | How it feels on your side | Suits | Watch out for |
|---|---|---|---|
| Open coil | Bouncy, often firm at the shoulder | Guest beds, tight budgets | Little pressure relief, more motion transfer |
| Pocket sprung | Springs move one at a time, so the hip can sink without dragging the rest down | Warm sleepers, people who like some bounce | Thin top layers on cheaper models |
| Memory foam | Slow, close hug around the shoulder and hip | Side sleepers with pressure points, couples | Can feel warm; some people dislike the sinking feel |
| Hybrid | Foam on top, springs below | Most side sleepers, including heavier ones | Usually heavier and pricier |
| Latex | Springier than memory foam, lifts back quickly | People who want contouring but find foam too slow | Fewer options, often expensive |
Online brands sold in the UK, such as Emma, Simba, Eve and Otty, sell foam and hybrid mattresses with home trials. Trial lengths and returns rules differ, so read them before you order. Some weeks in, you'll know far more about how a mattress feels on your side than a few minutes lying on it in a showroom can tell you.
Signs your current mattress is the problem
- You wake with a numb or tingling arm on the side you sleep on.
- Your hip or shoulder aches in the morning and eases once you're up.
- You keep flipping from one side to the other through the night.
- There's a visible dip where you sleep, or you roll towards the middle.
The first three usually point to a mattress that's too firm. The last one means the mattress is worn out.
Before you replace it: where a topper fits
If your mattress is flat, supportive and less than a few years old but too hard at the shoulder, a topper is the cheaper fix. The DreamAlign Side Sleeper Mattress Topper is the Dosaze option made with side sleeping in mind. It adds a layer on top for your shoulder and hip to sink into, and the springs or base foam you already have stay in place underneath. If pressure points bother you more than your sleeping position does, for example if you change position a lot, the DreamAlign Pressure Point Relief Mattress Topper is the one to compare it with.
A topper won't rescue a mattress with a dip in the middle or broken springs. It takes on the shape underneath it, sag and all. In that case, put the money towards a new mattress instead. Dosaze doesn't sell mattresses, so we'd rather say so than sell you a topper that won't help.
The pillow half of the problem
A good side sleeper mattress still leaves a gap between your ear and the mattress, about the width of your shoulder. For most adults that's 10 to 15 cm (4 to 6 inches). If your pillow is too flat, your head drops and your neck bends down. Too tall and it tilts up. People who fold their pillow in half or tuck an arm under it are usually trying to fill that gap.
Why side sleepers usually want a firm pillow
Height only helps if the pillow keeps it. A soft polyester or down pillow can look 15 cm tall on the bed and squash to half that once your head is on it. Firm fills hold their height through the night:
- Solid memory foam holds a fixed shape and supports the neck evenly.
- Shredded foam can be adjusted by adding or removing fill, and lets more air through.
- Latex has a springier feel and tends to sleep cooler than memory foam.
- Buckwheat is very firm and mouldable, but heavy and noisy.
- Down and polyester are soft and usually compress too much for side sleeping.
Your mattress changes the height you need. On a softer mattress or with a topper, your shoulder sinks more, so the gap is smaller and a slightly lower pillow may be right. On a firm mattress, go higher.
Where the Dosaze pillow fits
The Dosaze Contoured Orthopaedic Pillow is a memory foam pillow shaped to follow the curve of the neck and help keep the spine aligned. It works for side, back and stomach sleepers, which helps if you start the night on your side and end it on your back. The cover is a naturally cooling, anti-microbial fabric and comes off for washing, the foam is CertiPUR-US certified, and it ships locally within the UK. It has a fixed contoured shape, so if you want to fine-tune the height yourself, a shredded-foam pillow is the type to look at.
Frequently asked questions
What mattress firmness is best for side sleepers?
Most side sleepers do best on medium or medium-soft. Lighter people often prefer softer, and heavier people usually need medium-firm with a deep comfort layer so their hips don't sink too far. Firmness labels vary between brands, so use a home trial where you can.
Is a firm mattress bad for side sleepers?
A very firm mattress often pushes back hard at the shoulder and hip, which can leave you with a numb arm or a sore hip. If you already own a firm mattress that's otherwise in good condition, a side sleeper topper can add the give it lacks. A firm mattress also usually means you need a higher pillow.
Is memory foam or pocket sprung better for side sleeping?
Memory foam gives the closest contouring around the shoulder and hip, while pocket sprung mattresses sleep cooler and feel bouncier. A hybrid combines a foam comfort layer with pocket springs and suits a lot of side sleepers. Pick based on whether you run warm and how much sink you like.
How high should a pillow be for a side sleeper?
As a starting point, look for a pillow that keeps around 10 to 15 cm (4 to 6 inches) of height once your head is on it. Broad-shouldered sleepers need the top of that range and smaller frames the lower end. A firm fill such as memory foam or latex keeps that height through the night.
Can a mattress topper fix a mattress that's too firm for side sleeping?
Yes, if the mattress underneath is still flat and supportive. A topper adds a softer layer for the shoulder and hip to sink into. It won't fix a sagging or broken mattress, because it follows whatever shape is beneath it.
