Pain when bending the knee may be caused by meniscus injury, ligament injury, knee arthritis and other diseases, patients can take medication, surgical treatment, rehabilitation exercises and other treatments to relieve. 1. Meniscus injury: For the pain when bending knee caused by meniscus injury, patients can take oral diclofenac sodium extended-release tablets, ibuprofen extended-release capsules and other non-steroidal anti-inflammatory drugs as prescribed by the doctor, and can also use topical creams such as indomethacin babuzha, flurbiprofen babuzha and other topical creams. Severe cases can also be treated surgically, with procedures such as meniscal suturing and meniscoplasty. After treatment, patients should follow the doctor’s instructions to carry out rehabilitation exercises, can be appropriate to flexion and extension of the knee, conducive to the recovery of the condition, but the amplitude should not be too large. 2. Ligament injury: ligament injury can also lead to the phenomenon, patients can follow the doctor’s instructions oral acetaminophen tablets, indomethacin tablets and other non-steroidal anti-inflammatory drugs. Patients with ligament rupture can also undergo surgical treatment, mainly taking arthroscopic minimally invasive surgery. After regular treatment, patients should take rehabilitation measures under the guidance of the doctor. Appropriate squatting, flexion and extension movements can help patients restore the function of the knee. 3. Knee arthritis: knee arthritis can also cause patients to have pain when bending the knee, patients can follow the doctor’s instructions for oral Erythroxib tablets, celecoxib capsules and other non-steroidal anti-inflammatory drugs, serious patients can also be taken to surgical treatment, surgical modalities are mainly fusion, osteotomy, arthroscopic clean-up surgery, and so on. Patients with symptoms of pain when bending the knee, may also be chondromalacia patella, goosefoot bursitis and other diseases, patients should consult a doctor in a timely manner, follow the doctor’s instructions for treatment, do not blindly use drugs.