What are the causes of knee pain when bending?

The knee may refer to the knee joint. Pain during knee flexion could be caused by prolonged posture maintenance, environmental stimuli, arthritis, meniscus injury, synovitis, and other factors. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under the guidance of a qualified physician. Specific analysis is as follows:

1. Prolonged maintenance of a single posture: Sitting or standing for extended periods can easily lead to stiffness in the muscles and ligaments surrounding the knee joint, resulting in pain when bending the knee. It is recommended to gradually increase daily physical activity, engage in moderate exercise such as tai chi or walking, and maintain proper sitting and standing postures.

2. Environmental stimuli: Environmental factors such as weather changes or uneven ground surfaces may affect knee joint health and cause pain during knee flexion. It is advisable to keep the knee warm, avoid prolonged activity in cold and damp environments, and choose flat surfaces for physical activities.

3. Arthritis: This may be related to aging, joint wear and tear, and other factors. Inflammatory changes in the joint may cause pain during knee flexion, often accompanied by symptoms such as joint swelling and stiffness. Patients are advised to take medications such as nimesulide granules, meloxicam capsules, or loxoprofen sodium tablets as prescribed by their doctor.

4. Meniscus injury: This may result from sports injuries, chronic overuse, or similar factors. The meniscus is a cartilage pad located within the knee joint. When damaged, it can easily cause the aforementioned symptoms, along with joint pain and swelling. Patients should follow medical advice and use medications such as glucosamine sulfate capsules, Shujin Huoxue tablets, or diclofenac sodium sustained-release tablets for treatment.

5. Synovitis: This is generally caused by joint overuse, pathogen infection, or similar factors. The synovium is a thin membrane covering the surface of the joint. When infected or irritated, it may cause pain during knee flexion, possibly accompanied by joint swelling. Patients are advised to take medications such as methylprednisolone tablets, ibuprofen capsules, or celecoxib capsules under a doctor’s supervision to alleviate symptoms.

In daily life, patients are encouraged to drink plenty of warm water, avoid strenuous exercise, ensure adequate local warmth, keep the affected area dry, and consume nutrient-rich foods such as eggs and milk, which may benefit recovery.