The common causes of pain caused by lifting heavy objects on the arm include lactic acid buildup, arm muscle strain, and epicondylitis of the humerus, etc. Usually, general treatment, medication, physical therapy, and surgery can be used to help relieve the pain. 1. Lactic acid buildup: Usually it can be relieved naturally after resting, and can be combined with local massage and hot compresses to promote lactic acid metabolism and relieve pain. 2. Arm muscle strain: seen when lifting heavy objects, improper force leads to arm muscle strain. Cold compresses can be applied within 72 hours after the strain, and should also reduce the activities of the arm, if necessary, take the brake, after 72 hours, change to hot compresses. Oral non-steroidal anti-inflammatory drugs, such as ibuprofen and celecoxib, can be taken when the pain is obvious. Physical therapy such as intermediate frequency electrotherapy and infrared therapy can also be used. 3. Epicondylitis of humerus: physical therapy such as microwave, far infrared, etc. can be used, see with non-steroidal anti-inflammatory drugs, such as meloxicam, celecoxib, etc., to help relieve the pain, and, if necessary, can also be taken to closed treatment. If the condition continues to worsen, or if conservative treatment is ineffective, surgical treatment only needs to be considered. The above medications need to be used under medical supervision. When the pain persists after lifting heavy objects in the arm, it is recommended to consult a doctor and receive appropriate treatment.