The feeling of a burning sensation in the knee is a common physical complaint that signals irritation within the joint or surrounding tissues. This discomfort is often a direct result of inflammation, where the body’s response to damage releases chemical mediators that sensitize local nerve endings. The intensity of the burning can vary significantly, ranging from a mild warmth to a severe heat, but it consistently suggests that an underlying structure is under distress. Understanding the origin of this symptom is the first step toward finding relief.
Common Causes Related to Movement and Strain
The most frequent causes of a burning knee relate directly to physical activity, overuse, or improper biomechanics that place excessive stress on the joint structures. Patellofemoral Pain Syndrome (PFPS), commonly known as “runner’s knee,” is a prime example, where burning pain is felt specifically around or under the kneecap. This sensation arises from the irritation of the cartilage and soft tissues beneath the patella, often due to poor tracking of the kneecap in its groove, which is exacerbated by activities like running, squatting, or climbing stairs.
Patellar Tendinitis, or “jumper’s knee,” involves inflammation of the tendon connecting the kneecap to the shinbone. Repetitive, forceful extension of the knee causes micro-tears in the tendon, leading to a localized burning sensation and tenderness directly below the patella. Similarly, Iliotibial Band Syndrome (ITBS) causes a burning sensation on the outside of the knee. This occurs when the thick band of tissue running along the thigh becomes tight and rubs against the bony prominence on the side of the knee joint during repetitive motion. These mechanical conditions are often relieved by rest, which reduces the friction and strain causing the inflammation.
Chronic Conditions and Joint Inflammation
When the burning sensation persists, even when the joint is at rest, it may point toward chronic conditions involving long-term degradation or systemic inflammation. Osteoarthritis (OA) is a degenerative condition where the protective cartilage in the knee joint wears away over time. This loss of cushioning can lead to bone-on-bone friction. The resulting inflammation and irritation of the nerves in the underlying bone tissue can manifest as a burning or grinding sensation.
Rheumatoid Arthritis (RA) is an autoimmune disease where the body mistakenly attacks the joint’s synovial lining. This systemic attack causes the lining to become inflamed, resulting in persistent swelling, warmth, and a throbbing, burning pain. RA is often symmetrical, affecting both knees. The presence of inflammatory chemicals in the joint space contributes to the intensity of the burning sensation.
Bursitis is the inflammation of the small, fluid-filled sacs called bursae that cushion the joint. When a bursa is irritated by repeated pressure, such as excessive kneeling, it swells. This generates a localized burning pain, usually on the front of the knee.
Burning Sensation Caused by Nerves or Infection
A burning sensation that feels superficial or is accompanied by tingling and numbness may indicate a problem with the nerves supplying the leg. Peripheral neuropathy involves nerve damage, often due to systemic issues like diabetes, causing them to misfire and send pain signals described as burning or pins and needles. Referred pain from a compressed nerve in the lower back or hip can also travel along the nerve pathway, causing the burning symptom in the knee.
A more serious cause is an infection within the joint, known as septic arthritis. This condition is an urgent medical matter, as bacteria can infect the joint space, leading to rapid and severe joint destruction. The burning is intense and is accompanied by a rapid onset of symptoms, including high fever, severe redness, and extreme warmth over the joint. The body’s inflammatory response quickly increases pressure within the joint, causing severe pain and burning.
When to Seek Medical Attention and Home Care
For acute, mild burning knee pain related to activity, initial home care can be highly effective in managing symptoms. The RICE method—Rest, Ice, Compression, and Elevation—is the standard first-line treatment for reducing acute inflammation and swelling. Applying ice for 15 to 20 minutes several times a day constricts blood vessels and helps decrease the burning sensation. Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, can also help reduce inflammation and relieve discomfort.
It is important to seek professional medical attention if the pain does not improve after a week of conservative home care, or if the pain begins to impact daily activities or sleep. See a primary care physician if the knee is visibly swollen, locks up, or if you are unable to bear full weight on the leg. Immediate, emergency medical care is required if the burning pain is accompanied by severe warning signs. These signs include a high fever, chills, rapid swelling, or intense redness and heat that suggests a joint infection.