Knee Pain at Night? Here's What Your Body's Trying to Tell You

An ache or a twinge in your knee can interfere with your ability to sleep soundly. So if you're plagued by nighttime knee pain, you'll want to get to the bottom of it, and quickly.

Knee pain at night usually stems from an underlying condition or injury, Steven Yoon, MD, a board-certified physiatrist and director of the Regenerative Sports and Joint Clinic at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles, California, tells LIVESTRONG.com.

"Most conditions that cause knee pain can occur regardless of the time. It's just that the pain may be more noticeable at night," Dr. Yoon says.

Here's a look at some of the most likely culprits, plus what you can do to feel better.

It's not uncommon for knee discomfort to flare up in the evening as you're trying to sleep. That's partly because you're more likely to notice painful sensations when you don't have your daily activities to distract you.

Physiologic elements are also at play. "There's some evidence that inflammatory mediators in the knee elevate at night, and the body's natural cortisol levels that may decrease inflammation in the knee decrease at night," Dr. Yoon says.

Lying down deactivates your knee muscles, which can increase inflammatory mediators too.

So what kinds of underlying problems might trigger knee pain that feels worse once you get into bed? According to Dr. Yoon, these are the most common culprits.

As a form of wear-and-tear arthritis that becomes more common with age, knee osteoarthritis (OA) happens when the cartilage that cushions your joints begins to break down. That can happen from repeatedly putting stress on your knees from high-impact activities or carrying excess weight, notes the Centers for Disease Control and Prevention (CDC).

The loss of cushioning can make your knees feel painful and stiff, as well as cause swelling. The discomfort can be especially noticeable at night, with around 70 percent of people with knee OA reporting trouble sleeping, per the Arthritis Foundation.

Chrondromalacia, or damage to the cartilage under the kneecap, often causes pain or tenderness in the front of your knee that gets worse when you go up or down steps, kneel or squat. But like other knee problems, it can also flare up at night, Dr. Yoon says.

Chondromalacia mostly happens in younger adults. It usually stems from an injury, like fracturing your kneecap or badly twisting your knee from running, skiing, soccer or cycling. But people who spend a lot of time on their knees, like if you're a carpet setter or tile layer, can also be affected, per Harvard Health Publishing.

If you play a sport that involves a lot of jumping, like basketball or volleyball, you're more likely to get patellar tendinitis, or jumper's knee. It happens when the patellar tendon, which connects your kneecap to your shin bone, gets stressed from overuse and start to tear, says the Mayo Clinic.

Patellar tendinitis causes pain between your kneecap and your shin bone. It might be mild at first, but it tends to get worse as you continue doing the activity that caused the injury.

People who play contact sports are at risk for a meniscus tear, a common knee injury that can happen when quick pivots or forceful twisting cause tears in the knee tissue.

The injury usually starts with a popping sensation, with increasing pain, swelling and stiffness coming on over the course of two to three days, notes the American Academy of Orthopaedic Surgeons (AAOS).

As the injury worsens, your knee might start to feel like its locking up or giving out from under you.

A dull pain around the front of the knee that's accompanied by a rubbing, grinding or clicking sound when you move your knee could be patellofemoral syndrome, or runner's knee.

It can happen from overuse (from running or walking, for example), especially if your feet tend to roll inward when you run or if you have tight hamstrings or tight Achilles tendons, according to Johns Hopkins Medicine.

Most knee problems will get better with rest and time. In the meantime, there are some things you can do to reduce your discomfort at night and sleep easier.

Oftentimes, minor knee injuries will heal on their own if you go easy on the area for a while. But you should let your doctor know if at-home measures aren't helping, or if your pain is getting worse, says Dr. Yoon.

They can examine your injury to help you determine if treatments like physical therapy, steroid injections or even surgery could be helpful.