Do your knees feel fine when you go to bed but then in the middle of the night you awaken in pain?

How could sleeping soundly lead to knee pain?

Did you overlook a recent trauma to the knee?

“The sudden onset of knee pain could represent an acute injury [e.g., meniscus tear from a slip-and-fall] that was possibly unrecognized, such as a mild miss-step or twist that may have led to swelling and pain,” says John-Paul H. Rue, MD, orthopedic sports medicine surgeon with Orthopedics and Joint Replacement at Mercy Medical Center in Baltimore, MD.

But what if the overnight pain is in both knees or there hasn’t been any trauma?

“Knee pain can also develop suddenly if you recently started a new activity or increased your activity, such as walking a long distance or doing a new activity,” says Dr. Rue.

“An acute infection in the joint, known as septic knee, could be another cause of sudden new-onset knee pain without trauma.

“Warning signs would be swelling, pain, and increased warmth in the knee, and it is typically associated with a fever and generally not feeling well.”

A patellar tracking problem (more common in women) can also trigger pain in the knee that develops overnight, such that if you awaken in the middle of the night when nature calls, you realize “Geez, my knee!”

A tracking issue with the patella (kneecap) is usually caused by sport, and this can really hurt, though avoidance of the offending activity (which is usually running or jumping) should clear up this problem.

If your knee pain subsides once you’re up and about in the morning, it’s probably nothing to worry about.

But if the discomfort begins to occur during waking hours, you may have bursitis, osteoarthritis or chondromalacia patella (wearing down of the cartilage beneath the kneecap).

In fact, a certain kind of bursitis can cause overnight knee pain.

You may also want to experiment with different leg positions when sleeping. Perhaps the knee is simply reacting to a less-than-ideal position overnight and gets stiff as a result.

Dr. Rue specializes in prevention and treatment of sports and exercise injuries. His primary focuses are knee, shoulder and elbow injuries including ACL and cartilage injuries, rotator cuff injuries and overuse tendonitis.