How long it takes to recover from a knee fall with bruising and effusion needs to be judged according to the severity of the injury, mild patients can recover in 2-4 weeks; severe patients may need 8-12 weeks to recover. If the bruising and fluid accumulation around the knee joint is caused by soft tissue injury around the knee joint, the vast majority of them can subside in about 2-4 weeks, because generally the edema caused by soft tissue injury, the body’s ability to self-repair and absorption is relatively fast, and the time to return to normal will also be relatively short. If the above symptoms are caused by meniscus injury or cartilage injury, the recovery period is often longer, and the majority of patients may need 8-12 weeks to recover. Because the meniscus and cartilage in the knee joint are not supplied with blood, it takes longer to return to normal. If the symptoms of bruising and effusion after a knee injury do not resolve, or are accompanied by other symptoms, patients should go to the hospital in a timely manner, to identify the cause of the injury and then provide targeted treatment.