If the arm hurts all of a sudden, you need to take the following treatment: 1. First, use a cold compress on the painful area. It is recommended that ice be applied for 10-20 minutes. 2. After the cold compress is applied, it is recommended that the patient find a triangular scarf or a larger scarf and suspend the forearm in front of the chest, keeping the elbow joint flexed at 90 degrees. At this time, do not use this side of the upper limb to carry things or hold weight.3. Patients can apply topical ointment with blood circulation and blood stasis effect on the painful area. The recommended ointment for this area is wound and dampness pain relief cream, blood circulation pain relief cream, Yunnan Baiyao cream and so on. If the patient feels the pain is more intense, he can also take oral diclofenac sodium, ibuprofen and other drugs to reduce inflammation and pain.4. After the above treatments, if there is no significant relief within 3 days, the patient needs to go to the orthopedic department of a secondary or higher hospital for consultation to clarify the cause and then target treatment. For the above symptoms, there may be strains of the tendons of the upper limbs, or fatigue injuries of the tendon stops. For tendon injuries, the decision of whether to take conservative treatment or surgical treatment should be based on the specific degree of injury. For fatigue injury of the tendon stop, conservative treatment is the main treatment, followed by local painful point closure or small needle treatment.