A burning sensation in the knee can signal various underlying issues. While often mild and temporary, it can also indicate more significant problems. Understanding the potential causes, from common joint issues to nerve-related conditions, is the first step toward finding relief.
Understanding the Sensation
A burning sensation, known as paresthesia, indicates irritated or overstimulated nerve endings. This discomfort can arise from various mechanisms. Inflamed tissues release chemicals that sensitize local nerves, leading to a burning feeling. Increased blood flow, often part of an inflammatory response, can also contribute to warmth or burning. Mechanical compression or damage to nerves directly interferes with their normal signaling, which the brain interprets as burning pain.
Common Joint and Tissue Causes
Common causes of burning knee pain involve the joint or surrounding soft tissues, often due to overuse, injury, or wear and tear. Repetitive activities, such as sports, can lead to overuse injuries where tendons or bursae become inflamed, manifesting as a burning sensation.
Tendinitis, an inflammation of a tendon, is a frequent cause. Patellar tendinitis, or “jumper’s knee,” causes burning and pain below the kneecap due to overuse. Quadriceps tendinitis inflames the tendon above the kneecap, causing warmth or burning pain with knee movement.
Bursitis involves inflammation of the bursae, small fluid-filled sacs that cushion joints. When bursae around the knee become inflamed, it can lead to burning pain and noticeable swelling. Arthritis, particularly osteoarthritis, can also cause a burning sensation as protective cartilage deteriorates, leading to bone-on-bone contact and joint inflammation.
Meniscus tears, injuries to the knee’s cartilage pads, can result from blunt force or forceful twisting, causing irritation and a burning feeling. Patellofemoral pain syndrome, or “runner’s knee,” often causes burning pain around or under the kneecap due to irritation or improper kneecap tracking.
Nerve-Related Causes
Nerve irritation or damage around the knee can lead to a burning sensation, originating directly from the nerves themselves.
Nerve entrapment occurs when a nerve is compressed or pinched, causing pain, numbness, or burning. The saphenous nerve, running along the inner thigh and knee, can become entrapped or irritated, leading to a dull ache or burning sensation on the inside of the knee and lower leg. Common peroneal nerve compression can also result in burning sensations in the leg and foot.
Referred pain from the lower back is another source of nerve-related burning in the knee. Sciatica, caused by sciatic nerve compression (often due to a herniated disc or spinal stenosis), can lead to a sharp, burning pain that travels down the leg and may be felt in or around the knee. The pain is perceived in the knee because affected nerves extend to that area.
Neuropathy, or nerve damage, also manifests as burning sensations. Diabetic neuropathy, where high blood sugar levels damage nerves throughout the body, can affect leg nerves, resulting in chronic burning pain. Other forms of peripheral neuropathy, caused by various medical conditions or deficiencies, can similarly lead to burning feelings.
Other Less Common Causes
Certain systemic or more serious conditions can also cause a burning sensation in the knee. Infections within the joint, such as septic arthritis, can lead to intense burning accompanied by redness, swelling, and warmth. Cellulitis, a bacterial skin infection, can also cause significant burning and inflammation in the surrounding tissues.
Complex Regional Pain Syndrome (CRPS) is a chronic pain condition that can develop after an injury or surgery. It is characterized by severe, prolonged burning pain, swelling, and changes in skin temperature or color. This condition involves dysfunction of the nervous system.
Vascular issues can sometimes contribute to knee burning. Peripheral artery disease (PAD), where narrowed arteries reduce blood flow to the limbs, can occasionally cause a burning sensation, particularly during activity. Deep vein thrombosis (DVT), a blood clot in a deep vein, primarily causes swelling and pain, but localized warmth and a burning sensation might also occur.
When to Seek Professional Guidance
While some instances of knee burning may resolve with rest and home care, certain signs indicate the need for professional medical evaluation. If the burning sensation persists despite self-care measures, or if it worsens over time, consulting a healthcare provider is advisable.
Seek immediate medical attention if the burning pain has a sudden onset accompanied by severe swelling, or if you cannot bear weight on the affected knee. Additional red flags include fever, chills, or a general feeling of illness alongside the knee symptoms, which could suggest an infection. Any new numbness, tingling, or weakness in the leg or foot, or visible deformity or significant bruising around the knee, also warrants prompt medical assessment. A professional diagnosis is important for determining the cause and establishing an appropriate treatment plan.