The ligaments of the knee mostly refer to the anterior and posterior cruciate ligaments and the medial and lateral collateral ligaments of the knee joint. After a ligament injury due to strenuous exercise, trauma, etc., symptoms such as bleeding, swelling, and pain occur. Twenty days after the ligament injury, the ligament still feels swollen and painful common reasons are too early activities, injury is too heavy. 1. Premature activities: knee ligament injury without adequate rest, premature weight-bearing exercise or premature hot packs, may lead to swelling does not reduce or even aggravate, should be appropriate to elevate the lower limbs to promote swelling, and reduce the activities, adequate rest, is conducive to the recovery of the injury. 2. Excessive injury: because the injury is too heavy, resulting in longer ligament recovery time or ligament rupture is difficult to recover, there may be swelling difficult to subside, you need to take oral non-steroidal anti-inflammatory drugs, such as diclofenac sodium delayed-release tablets, etc., and the ligament rupture needs surgery to rebuild the ligament. Knee ligament strain swelling after not see relief for more reasons, may also be related to vascular occlusion and other diseases, it is recommended to consult a timely, clear cause, targeted treatment.