If you wake up with a sore shoulder and you have not lifted anything heavy or changed your workout, your pillow is a prime suspect. It sounds strange that the thing under your head could ache your shoulder, but for side sleepers it happens constantly.
The mechanics, in plain terms
When you lie on your side, your bottom shoulder takes your body weight while your head needs support to stay level with your spine. Get the pillow height wrong and two things go wrong at once. Your neck bends out of line, and the muscles that run from your neck across the top of your shoulder, the trapezius, stay tensed all night trying to hold your head up. You wake up with a shoulder that feels knotted, even though the real problem started at your neck.
Too low is the usual culprit
A pillow that is too thin lets your head sag toward the mattress. That collapses the space your shoulder needs and crams the joint, while straining the neck muscles above it. A pillow that is too high tips your head the other way and pinches the top of the shoulder. The sweet spot is a height that fills the exact gap between your ear and the mattress so your head floats level and your shoulder carries only your body weight, not your head too.
Why one fixed pillow rarely nails it
Your shoulder width, your mattress firmness, and your sleep position all change how much loft you need. A pillow built for an average shoulder leaves most people slightly off, and slightly off every night becomes a daily ache. This is the case for an adjustable pillow. You add shredded fill until your head is level and the shoulder strain disappears, then leave it there. Dreamy Blue pillows ship overfilled for exactly this reason, so you can build the height up to your shoulder instead of hoping a fixed pillow is tall enough.
A quick test
Lie on your side as you normally sleep and have someone check you from behind. If your head is dropping toward the bed, your shoulder is doing extra work. Add fill until your neck runs in a straight line with your spine. Most people feel the shoulder strain ease the first night.
When it is not the pillow
Persistent shoulder pain that does not change with your pillow, comes with weakness, or radiates down the arm deserves a doctor, not a new pillow. But for the common case of waking up stiff and sore on your sleep side, fixing your loft is the first and cheapest thing to try.
Not sure what height you need? Take our 60-second sleep quiz and we will match you to the right pillow and a starting loft for how you sleep.
Keep reading
- The Best Pillow for Side Sleepers With Neck Pain
- Firmer or Softer: Which Pillow Is Better for Neck Pain?
- Can Your Pillow Cause Tension Headaches?
Take the 60-second sleep quiz or explore The Sapphire gusseted pillow.