There are many reasons for knee creaking when straightening, the common ones are overwork, meniscus injury, knee degeneration, etc. Different treatments should be chosen according to different causes. The treatments available include resting more, avoiding overwork, conservative treatment and surgery. 1. Excessive exertion: Doing long time work with heavy force on the knee, or holding the knee in a half-bent position for too long may cause the knee to rattle when it is bent and straightened. First of all, pay attention to rest, avoid overwork of the knee joints, should also pay more attention to the activities of the knee joints in daily life, exercise, avoid keeping the bending posture for too long. 2. Meniscus injury: after meniscus tear, when the knee joint is flexed and extended, the damaged meniscus will be squeezed, which will lead to creaking sound when moving. For meniscus injury is light, you can choose conservative treatment, take some non-steroidal anti-inflammatory drugs, such as aspirin, ibuprofen to relieve pain and promote joint swelling. If the damage is more serious, surgery is needed. 3. Knee degeneration: also known as osteoarthritis, due to the reduction of joint fluid, destruction of cartilage, osteomalacia of the knee joint and some other pathological changes lead to chronic inflammation, and the sound will appear when you move. Its treatment can generally choose physical therapy such as acupuncture or massage to relieve the symptoms, but also can choose to paste ointment or take anti-inflammatory pain medication such as ibuprofen, etc., but also can choose surgical treatment such as artificial replacement arthroplasty. There are other reasons why your knee creaks when you straighten it, so it is recommended that you seek medical attention to identify the cause of the problem and carry out targeted treatment.