What causes soreness and swelling in the knees?

Knee soreness and swelling may be caused by physiological factors, or could result from pathological conditions such as synovitis or rheumatoid arthritis. The specific causes are analyzed as follows:

1. Physiological Causes

If one walks or stands for prolonged periods, normal blood circulation may be affected, leading to excessive lactic acid production. When tissues do not receive adequate blood supply or are irritated by acidic substances, a sensation of soreness and swelling may occur. This discomfort can be relieved through methods such as warm compresses and massage. Adequate rest and avoiding prolonged standing are also recommended.

2. Pathological Causes

1) Synovitis

If the knee area is affected by trauma or infection, inflammatory changes may develop in the joint's synovial membrane, causing dysregulation of synovial fluid secretion and resulting in fluid accumulation (effusion). This often leads to symptoms such as redness, swelling, heat, and pain. Treatment may include joint cavity irrigation or non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen sustained-release capsules or diclofenac sodium sustained-release capsules to alleviate symptoms.

2) Rheumatoid Arthritis

When the body's immune system becomes dysfunctional, joint tissues may be attacked, leading to knee joint swelling, restricted movement, and pain. Medications such as celecoxib capsules or methylprednisolone tablets may be used under medical guidance, along with physical therapy.

Besides the common causes mentioned above, gout cannot be ruled out. It is recommended to undergo magnetic resonance imaging (MRI) for further evaluation.