Knee swelling is one of the most common complaints among people of all ages—from athletes and fitness enthusiasts to older adults dealing with chronic joint conditions. While it may seem like a minor inconvenience at first, persistent or severe swelling can signal more serious underlying issues.
To help clarify what causes knee swelling and how it can be effectively treated, we turn to Jordan Sudberg, a leading pain management specialist with extensive experience in diagnosing and treating musculoskeletal pain. According to Dr. Sudberg, “Knee swelling is not just a symptom—it’s your body’s way of telling you something’s wrong. Ignoring it can lead to long-term damage and reduced mobility.”
Let’s dive deeper into the most common causes of knee swelling and the treatments Dr. Sudberg recommends.
What Is Knee Swelling?
Knee swelling, also known as knee effusion or “water on the knee,” occurs when excess fluid builds up in or around the knee joint. This can cause:
- Visible puffiness or enlargement of the knee
- Stiffness and difficulty bending or straightening the leg
- Pain or tenderness, especially when weight-bearing
- A feeling of warmth or heat around the joint
Jordan Sudberg emphasizes that swelling is usually the result of inflammation, which can stem from a variety of sources.
Common Causes of Knee Swelling
1. Injury or Trauma
Sprains, ligament tears (like ACL or MCL injuries), or meniscus tears are often accompanied by immediate swelling. The body sends fluid to the area to protect it and begin healing.
Dr. Sudberg’s Tip: “After an acute injury, swelling within the first few hours is a clear sign something more serious might be going on. Early diagnosis and imaging can prevent long-term joint damage.”
2. Overuse or Repetitive Stress
Athletes and active individuals may experience swelling due to repeated strain on the joint, especially without adequate recovery time.
3. Arthritis
Both osteoarthritis and rheumatoid arthritis are major culprits of chronic knee swelling. Osteoarthritis results from wear and tear, while rheumatoid arthritis is autoimmune in nature.
4. Bursitis
Inflammation of the bursae—small fluid-filled sacs that cushion the knee—can result in localized swelling, often around the kneecap.
5. Infection
Though less common, septic arthritis can cause sudden, severe swelling and requires urgent medical treatment. Fever and redness are often additional warning signs.
6. Gout or Pseudogout
These conditions result from crystal deposits in the joint and can cause painful, sudden-onset swelling. Dr. Sudberg warns that misdiagnosis can lead to unnecessary long-term pain.
How Is Knee Swelling Diagnosed?
According to Jordan Sudberg, proper diagnosis is key to effective treatment. “You can’t treat swelling the same way across the board. The underlying cause dictates everything—from medication to physical therapy.”
Diagnosis may include:
- Physical examination
- Patient history
- Imaging (X-rays, MRI, or ultrasound)
- Joint aspiration (removing fluid for analysis)
Treatment Options for Knee Swelling
1. R.I.C.E. (Rest, Ice, Compression, Elevation)
This tried-and-true method is ideal for mild injuries or post-activity swelling. It helps reduce inflammation and supports early healing.
2. Medication
- NSAIDs (like ibuprofen or naproxen) for inflammation and pain
- Corticosteroids, either oral or injectable, to rapidly reduce inflammation
- Antibiotics, if an infection is present
- Colchicine or allopurinol for gout-related swelling
Dr. Sudberg advises caution with long-term NSAID use: “They’re effective, but overuse can harm the kidneys or stomach lining. Use under guidance.”
3. Aspiration
In some cases, fluid may be drawn out of the knee to relieve pressure and analyze for infection, gout, or bleeding.
4. Physical Therapy
Rebuilding strength, flexibility, and balance is crucial—especially after injury or with chronic arthritis. Dr. Sudberg often refers patients to physical therapists as part of a long-term care plan.
5. Bracing or Assistive Devices
Supportive braces can stabilize the knee during recovery. Cane use may be suggested for those with significant joint degeneration.
6. Surgery
In cases of torn ligaments, cartilage damage, or advanced arthritis, surgery may be necessary. Options include arthroscopy, partial knee replacement, or total knee replacement.
When to See a Doctor
Dr. Sudberg emphasizes not to ignore persistent or worsening symptoms. “If swelling lasts more than a few days, or comes with fever, extreme pain, or reduced mobility—see a doctor. Early intervention can save your knee in the long run.”
Final Thoughts
Knee swelling can be a temporary nuisance or a sign of a deeper issue. The key is early recognition and expert care. With the guidance of specialists like Jordan Sudberg, patients can navigate treatment with confidence and get back to the activities they love.
“Your knees carry you through life,” says Dr. Sudberg. “Take care of them—and don’t wait until it’s too late to start listening to what they’re telling you.”