Knee Pain at Night: What It Means When It Wakes You Up
When a patient tells me their knee wakes them up at night, it’s usually a sign of severe arthritis. Once arthritis is affecting your sleep, it’s affecting your quality of life, and it’s time to come in. Here’s what knee pain at night usually means, why I’m careful about the pillow under the knee, and how to sleep in the meantime.
Key takeaways
- Knee pain that wakes you up at night is usually a sign of severe arthritis.
- When arthritis affects your sleep, it’s affecting your quality of life. That’s usually the time to come in and be evaluated.
- A pillow under the knee can feel better, but sleeping with the knee bent can quickly cost you the ability to fully straighten it.
- Arthritis itself tends to make a knee lose straightening, through swelling, a tight joint capsule, and bone spurs.
- There’s no proven best sleeping position. Most of my patients are most comfortable on their side with a pillow between their legs.
When a patient tells me their knee wakes them up at night, it’s usually a sign of severe arthritis. It’s very similar to what I tell patients about hip pain at night: once arthritis is affecting your sleep, it’s affecting your quality of life, and it’s time to come in.
What knee pain at night usually means
During the day you’re moving and distracted. At night, lying still lets an arthritic knee stiffen, and the pain is harder to ignore. By the time a knee is waking someone up, the arthritis is usually pretty severe, and often bone-on-bone.
That doesn’t mean surgery is decided in the first visit. It means it’s time to be evaluated, with an exam and X-rays, and to talk about the treatment options. For the rest of what I look for, see signs you need a knee replacement.
“I can deal with it during the day, but at night it just throbs.”
“I can’t find a position where my knee is comfortable.”
“Every time I roll over, it wakes me up.”
“I’m not sleeping through the night anymore.”
“I sleep with a pillow under my knee, and now it won’t straighten all the way.”
The pillow under your knee: a big caveat
If you’re lying flat on your back, a pillow under the knee bends it a little, and that often feels better. I understand why people do it.
But there’s a big caveat. If you sleep with your knee bent, on a pillow or otherwise, you can very quickly lose the ability to fully straighten it. That’s called a flexion contracture, and an arthritic knee is already prone to it. A knee that won’t straighten all the way makes walking harder.
Don’t sleep with the knee bent
A pillow under the knee for a short rest is one thing. Sleeping that way night after night can leave you with a knee that won’t straighten.
Why arthritic knees stop straightening
Arthritis itself tends to cause flexion contractures, in a few ways:
- Swelling. Arthritic knees are prone to swelling, and the swelling tightens the capsule and other structures around the knee.
- Bone spurs. Arthritis creates bone spurs, which tighten things further.
- Tight muscles. Over time, the muscles around the knee tighten along with everything else.
Put those together, and an arthritic knee slowly loses its ability to fully straighten. Sleeping with it bent speeds that up.
How to sleep with knee pain tonight
There’s no single recommended way to sleep, and no study has proven one position is best. Here’s what I tell my patients:
What most of my patients find comfortable
- Sleep on your side with a pillow between your legs
- The pillow keeps one knee from pressing or rubbing on the other, which many people with arthritis on the inner side of the knee don’t like
- Avoid sleeping with the knee bent on a pillow night after night
That’s based on what my patients tell me is most comfortable, not on research. And it only helps you get through the night; it doesn’t fix the cause.
What to do next
If your knee is waking you up at night, come in. An exam and X-rays tell us how severe the arthritis is and what will help. That might be physical therapy and other nonsurgical care, an injection with cortisone, gel, or PRP, or, when the arthritis is severe, a partial or total knee replacement.
Get seen promptly if…
The knee is hot, red and very swollen, you have a fever, or you can’t put weight on it after an injury. That isn’t typical arthritis pain and shouldn’t wait.
Get your nights back
I see patients in Washington, D.C. and Germantown, Maryland. Request an appointment.
Frequently asked questions
Why does my knee hurt at night?
When knee pain wakes you up at night, it’s usually a sign of severe arthritis. During the day you’re moving and distracted. At night, lying still lets an arthritic knee stiffen, and the pain is harder to ignore.
Does knee pain at night mean I need a knee replacement?
Not always, but it means it’s time to be evaluated. When arthritis is waking you up, it’s usually pretty severe and it’s affecting your quality of life. An exam and X-rays tell us what’s going on and which treatment options make sense, which may include a knee replacement.
Should I sleep with a pillow under my knee?
It can feel better, because a pillow under the knee bends it a little when you’re lying flat. But there’s a big caveat. Sleeping with your knee bent can quickly cost you the ability to fully straighten it, called a flexion contracture. An arthritic knee is already prone to that, so I’m careful about it.
Why won’t my arthritic knee straighten all the way?
Arthritis tends to cause it. Arthritic knees swell, and the swelling tightens the capsule and other structures around the knee. Arthritis also creates bone spurs, which tighten things further. Over time the knee loses its ability to fully straighten. Sleeping with the knee bent on a pillow can speed that up.
What is the best sleeping position for knee pain?
There’s no single recommended way to sleep, and no study has proven one position is best. Most of my patients are most comfortable on their side with a pillow between their legs, which keeps one knee from pressing or rubbing on the other. That’s based on what my patients tell me, not on research.
Is knee pain at night different from hip pain at night?
Not much. In both, night pain usually means the arthritis is severe and it’s time to come in. The main knee-specific concern is losing the ability to fully straighten the knee, especially if you sleep with it bent.
When should I see a doctor for knee pain at night?
If your knee is waking you up at night, come in. Get seen promptly if the knee is hot, red and very swollen, if you have a fever, or if you can’t put weight on it after an injury.
References
This article is for general education and is not a substitute for personalized medical advice. Please consult Matthew Harb, M.D. about your specific condition.
What patients say
“I walked into the surgical center in great pain and walked out with a new knee and a renewed person.”
“My full knee replacement is a big success — six months after surgery I’m hiking and kayaking again.”
“An amazingly talented surgeon who performed my total knee replacement with a spectacular outcome.”
Where to go from here
Signs You May Need a Knee Replacement
Most people with knee arthritis don’t need surgery any time soon — and surgery is rarely the first step. But it helps to recognize when arthritis is genuinely limiting your life, because with a knee replacement, you largely decide when it’s time. The decision is driven by your pain, function, and quality of life — not by an X-ray.
Read articleArthritis & Joint PainBone on Bone Arthritis: Do You Need Knee Replacement Surgery?
If you’ve been told you have “bone-on-bone” arthritis, the first question is usually whether you need a knee replacement. The answer may surprise you: not necessarily. A severe X-ray is only part of the picture — what matters far more is how the arthritis is affecting your life. We treat patients, not X-rays.
Read articleArthritis & Joint PainBone Spurs in the Knee: What They Are and What They Actually Mean
A bone spur in the knee — a knee osteophyte — is extra bone the body builds along the edges of the joint as cartilage wears away. It is almost never the cause of your pain. It is a marker that the knee has been carrying load abnormally for years, which is why removing a spur on its own rarely helps and why arthroscopic "clean-out" surgery for arthritic knees has largely been abandoned. The spur matters as a clue about the arthritis behind it, and that arthritis is what we actually treat.
Read articleWondering what’s causing your hip or knee pain?
Schedule an evaluation with Dr. Harb to understand your diagnosis and build a plan — from nonsurgical care to replacement, when the time is right.
Not ready to book? Read how to choose a hip or knee surgeon