Section
Pillows
Height and shape matter more than material — and the centimetre figures in retail copy are not derived from anything.
Pillows get a fraction of the attention mattresses do and cause a comparable share of the complaints. They are also the one part of the bed where the research is unusually clear about what matters — and unusually at odds with how they are sold.
What the evidence shows
A 2021 review pooling nine high-quality trials across 555 participants found that height and shape matter more than material for keeping the neck aligned. The same review found that pillow design showed no significant effect on sleep quality in people with chronic neck pain.
That is worth sitting with, because it cuts against most of what is on the shelf. Memory foam, latex, down, microfibre, bamboo, cooling gel — the material is the thing brands compete on, and it is the variable the evidence is least excited about.
There is no validated figure for correct pillow height by sleeping position. The centimetre recommendations you will find in retail copy — so many centimetres for side sleepers, so many for back — do not appear to be derived from any study or published standard that we could trace. They may well be sensible rules of thumb drawn from fitting experience; they are not measurements.
What actually helps
The practical test is the same one that works for mattresses: get someone to look at you from behind while you lie in the position you actually sleep in. On your side, your nose should sit in line with the centre of your chest, not tilted up or dropped down. On your back, your chin should not be pushed toward your chest.
Side sleepers generally need more height than back sleepers, because there is a wider gap between the shoulder and the head to fill. That much follows from geometry rather than marketing. How much more depends on your shoulder width and how far your mattress lets the shoulder sink, which is why a pillow that suited your old bed may not suit a new one.
A word on claims
"Best pillow for neck pain" is one of the most searched phrases in this category and one of the most heavily regulated. No pillow sold in the UK is licensed to treat anything, and the Advertising Standards Authority expects clinical trials conducted on people before a product may claim to relieve pain. Persistent neck pain is a matter for a GP or physiotherapist.
More pillow guides are in preparation. In the meantime, the UK bed facts page covers fibre and moisture properties that apply to pillow fillings as much as to mattresses.