03 / Understand the area
Behind the knee
A tight feeling behind the knee and a swollen calf shouldn't be treated as the same problem until someone has assessed them.
An educational guide that covers the left and right sides alike. Where it hurts is a useful clue, but only a clue.
A useful starting point
What this area can tell you.
Symptoms behind the knee can come with a joint problem, a fluid-filled swelling or an irritated tendon nearby. A new swollen or painful calf also raises a circulation question, and that needs medical attention. The details that matter: any visible fullness, if bending or straightening is limited, and if swelling runs down the leg. The likely source needs to be found before anyone chooses exercises or hands-on treatment. And a lump isn't harmless just because it's near a sore knee.
Notice the pattern
Three questions to bring with you.
You don't need to know what it is before you come in. These are details that help when you tell us what you're feeling.
- Is there fullness behind the knee you can see or feel, and when did it appear?
- Does bending or straightening feel restricted, or is the main symptom calf pain?
- Is one calf more swollen, warm or discolored than the other?
When to get help sooner
New one-sided calf pain or swelling needs urgent medical assessment for a possible blood clot. If it comes with chest pain, breathlessness or fainting, seek emergency care immediately.
Follow the connection
Possible explanations. Better questions.
These guides cover conditions and patterns that may overlap with this area. Think of them as a place to start our conversation: no body map can tell you which one, if any, you have.
What the studies found, and where they stop
How the research fits this area.
Knee osteoarthritis research may inform care once that diagnosis is made. It doesn't evaluate a new swelling behind the knee or rule out a blood clot, and it must never delay a medical assessment.
How we select and explain sources ↗Follow the evidence
Research, with context.
Selected published sources behind what we've written, each with what it found and what it can't tell us. We give you both halves because no paper can diagnose you or predict how your own care will go.
Physical Therapy versus Glucocorticoid Injection for Osteoarthritis of the Knee
156 patients with knee osteoarthritis in the US military health system.
What it foundPatients assigned physical therapy had less pain and disability at one year than those assigned glucocorticoid injection.
What it can't tell usIt was a physical therapy trial in one particular setting. It doesn't show cartilage regeneration, and it doesn't vouch for every treatment offered for knee pain.
Publication details & citation
Deyle et al. Physical Therapy versus Glucocorticoid Injection for Osteoarthritis of the Knee. New England Journal of Medicine. 2020. DOI: 10.1056/NEJMoa1905877.
Read the publication record
Our editorial policy explains how to read these sources and what our clinical-review labels mean.
Your next step
Bring your questions.
We’ll start there.
Your answers to those three questions are where we start. We go over your history and symptoms, examine you, and explain what we found before we recommend anything. If it turns out to be something another doctor should look at, we'll tell you.
Anatomy: BodyParts3D, © DBCLS, CC BY 4.0. Model & rendering credits. Return to the full body explorer.