The pain on the front side of the big arm may be caused by epicondylitis of the humerus, osteoarthritis of the elbow joint and so on. 1. Epicondylitis of the humerus: commonly known as “tennis elbow”, is due to trauma, chronic strain injury, long-term repetitive force activities of the wrist (which can lead to excessive rotation of the forearm anteriorly or posteriorly) and other reasons, resulting in injury to the tendon and humerus epicondylar junction, and the gradual formation of aseptic inflammation, resulting in degenerative changes in the starting and ending points of the tendon, pain, swelling, decreased grip strength, joint popping and other symptoms. The symptoms include pain, swelling, weakening of grip strength and joint popping. 2. Osteoarthritis of the elbow joint: long-term use of the elbow joint, resulting in wear and tear of the articular cartilage, causing degenerative changes in the articular cartilage of the aseptic inflammation, can appear elbow joint pain, swelling, impaired mobility, in the activities of the elbow joint or cold pain aggravation, and even local popping. Pain in the anterior side of the big arm may also be caused by muscle strain, etc. It is recommended to consult a doctor in time for a clear diagnosis and targeted treatment under the guidance of the doctor.