The swelling and pain on the side of the left calf caused by trauma is treated differently because of the different degree of injury. Mild injuries are treated mainly by reducing swelling and relieving pain, while severe injuries can be treated by manipulative repositioning with plaster fixation and surgery. 1. For simple subcutaneous tissue, muscle, capillaries and other soft tissue injuries. The degree of such injuries is mild, can be intermittent cold compresses within 72 hours after the injury to promote vasoconstriction and reduce swelling; after 72 hours, the use of hot compresses to promote blood circulation and accelerate the absorption of hematoma. Oral non-steroidal anti-inflammatory drugs for pain relief, such as diclofenac sodium extended-release tablets. 2. For tibiofibular fracture, the treatment is different according to the degree of fracture. If the fracture is not seriously displaced, it can be fixed by manipulation and external fixation with plaster, while comminuted fracture or seriously displaced fracture needs surgery for internal fixation. If there is a combination of large blood vessel injury, corresponding surgical treatment is also needed. 3. For injuries to the patellar ligament, medial and lateral collateral ligaments and anterior and posterior cruciate ligaments caused by trauma, mild injuries can be treated conservatively with oral non-steroidal anti-inflammatory drugs for pain relief, such as diclofenac sodium delayed-release tablets, etc., while ligament rupture requires surgery for repair and reconstruction. When the side of the calf is swollen and painful due to trauma, it is recommended to consult a doctor in time, complete the relevant examination and then carry out targeted treatment. The use of drugs need to follow the doctor’s instructions.