There are many reasons for elbow pain when the arm is straightened, the common ones are trauma, osteoarthritis, humeral epicondylitis and so on.
1. Trauma: If the radius, ulna and humerus in the elbow joint are detached from the normal position or fractured under the action of external force such as fall, impact and violent pulling, resulting in abnormal joint structure and function, manifested as elbow joint pain, swelling, restriction when straightening, elbow pain when straightening the arm, mostly by joint deformity.
2. Osteoarthritis: the damage of articular cartilage is the main cause, which can involve the whole joint tissue, and the degeneration, fibrosis and fracture of articular cartilage will occur, which mainly manifests as joint pain, stiffness, hypertrophy and limitation of activity, and when it occurs in the elbow joint, the elbow joint may not be able to be straightened, and the elbow hurts when straightening the arm.
3. Epicondylitis of the humerus: due to trauma, chronic strain injury caused by part of the forearm muscles and the humerus epicondyle connection of the aseptic inflammation, the main manifestation is the gradual emergence of the lateral elbow joint pain, severe cases may have functional limitations, straightening the elbow pain.
There may be other reasons for elbow pain when straightening the arm, it is recommended to go to the hospital in time, under the guidance of the doctor to give targeted treatment.