Swelling and pain in the left knee joint, it is recommended that patients go to the hospital for a detailed examination, clear diagnosis after taking the appropriate formal treatment, you can also take brake rest, support symptomatic treatment observation, observation for a week if the effect is not good or should go to the hospital for consultation. At the same time, the knee joint should be moderately braked and fixed in life, it is best not to go down to the ground, to rest in bed, elevate the affected limb above the heart, you can take oral anti-inflammatory and analgesic drugs, commonly used non-steroidal anti-inflammatory drugs, such as diclofenac, celecoxib, loxoprofen, etc.. You can also take oral medications to protect joint cartilage, such as glucosamine sulfate, and local physical therapy, including baking electricity, spectrum irradiation, moxibustion, and hot compresses. After a week or so of braking and resting and supporting symptomatic treatment, if the symptoms are significantly relieved, you can continue the recuperation and observation, if the symptoms are not relieved, you should promptly go to the hospital.