Is it better to sleep with one or two pillows on your side?

One correctly sized pillow under the head. Two stacked pillows compress unevenly and shift overnight, so the height you fall asleep with is not the height you keep. If your pillow is too low, replace it with a taller or adjustable one instead of stacking.

Should side sleepers put a pillow between their knees?

Yes — it is one of the highest-value pillow additions. A pillow between the knees keeps the top leg from dragging the pelvis forward, which reduces hip and lower-back strain. A body pillow does the same job while also supporting the top arm.

Why do I sleep better with two pillows?

Usually because one pillow is too low and the second approximates the height you actually need. An adjustable or taller single pillow will deliver that height more consistently — stacks shift and flatten overnight.

Can sleeping with two pillows cause neck pain?

Yes. A stack is typically too tall, pushing the chin toward the chest and bending the neck upward all night — a classic cause of morning neck pain and base-of-skull headaches.

Should Side Sleepers Use One Pillow or Two?

5 min readUpdated September 2026

For your head, one pillow — almost always. Two stacked pillows are how people approximate the height of a pillow they do not own, and the stack shifts, compresses unevenly, and folds through the night. But there is a second-pillow question side sleepers should say yes to: the one between the knees. Here is when one is right, when two under the head can work, and where the useful second pillow actually goes.

In this guide

Why one pillow wins for your head
When two under the head can work
The second pillow side sleepers actually need
Signs you have the wrong count

Why one pillow wins for your head

A pillow stack is an unstable structure. The bottom pillow compresses more than the top one, the two slide against each other, and by morning the geometry you fell asleep with no longer exists. Your head has drifted, and your neck has spent hours adapting to a shifting surface.

A single pillow of the correct height holds its geometry all night. If your current pillow is too low and you are stacking a second to compensate, the better spend is one taller or adjustable pillow — the stack costs the same and performs worse.

When two under the head can work

There are two legitimate exceptions. The first is a deliberate layering strategy: a firm, supportive base pillow with a thin soft pillow on top for surface comfort — the hotel trick. This works because the bottom pillow is chosen for support and the top one only for feel.

The second is reading or watching TV in bed, where extra elevation is the point. Just do not fall asleep in that position; the chin-to-chest posture that is fine for twenty minutes of reading is a neck strain held for hours.

The second pillow side sleepers actually need

Between the knees. On your side, the top leg drops forward, rotating the pelvis and twisting the lower back — a major source of hip and lower-back ache in side sleepers. A pillow between the knees keeps the hips stacked and the spine neutral.

A firm knee pillow or a body pillow both work; body pillows add the bonus of parking the top arm, which unloads the shoulder. If you wake with hip or lower-back pain rather than neck pain, this is the pillow to add before touching the one under your head.

Signs you have the wrong count

Neck pain or headaches: your head setup is wrong — fix the single pillow's height rather than adding a second. Hip or lower-back pain: your head may be fine; add the knee pillow. Shoulder pain: check the top arm — a body pillow to hug is often the answer.

The general rule: pillows under the head are a precision instrument where more is worse; pillows around the body are supports where more is often better.

Pillows we recommend for this

Coop Home Goods Original

Side and back sleepers who want to dial in loft

9.4Read review

Coop Home Goods Body Pillow

Side sleepers, pregnancy, and hip alignment

8.9Read review

Pillow Cube Side Cube Original

Dedicated side sleepers with shoulder gap issues

8.6Read review

See the full ranking: Best Pillows for Side Sleepers

FAQ

Keep reading

RoundupBest Pillows for Back and Side SleepersOne pillow that handles the two most common positions — medium loft with enough give or adjustability to cover both.RoundupBest Pillows for Side and Stomach SleepersCompressible, adjustable pillows for sleepers who split the night between the tallest and lowest positions.GuideWhere to Put a Pillow for Lower Back Pain (Every Sleep Position)The right pillow placement depends on your sleep position: between the knees for side sleepers, under the knees for back sleepers, under the hips for stomach sleepers. Here's exactly where — and why it works.GuideFirm vs Soft Pillow for Side Sleepers: Which Is Right?Side sleepers need medium-firm support that holds loft under load — but firmness and height are different dials. Here's how to set each.GuideHow High Should a Pillow Be for a Side Sleeper?Most side sleepers need 4 to 6 inches of compressed loft — but shoulder width and mattress firmness move that number. Here's how to find yours.GuideIs It Better to Sleep Without a Pillow?Sleeping without a pillow can help some stomach sleepers and certain back conditions, but it makes side sleeping worse. Here's how to tell if going pillowless is right for you.

Get the Mr. Squish Pillow Cheat Sheet

A simple guide to choosing the right pillow based on your sleep position, body size, and comfort preferences.

No spam. Unsubscribe anytime.

Affiliate disclosure: Mr. Squish may earn a commission when you buy through links on this page. Recommendations are based on independent product research; any hands-on test is labelled separately. Learn more.