Swelling of the elbow joint can have several causes, including infection, injury and disease, according to WebMD. A common cause of elbow swelling is olecranon bursitis, an irritation of the bursa at the tip of the elbow. Gout and rheumatoid arthritis, as well as injuries, can lead to the development of olecranon bursitis.
Injuries, such as a fractures and sprains, can also cause swelling in the elbow area, according to WebMD. Additionally, various forms of arthritis, including psoriatic arthritis and reactive arthritis, can cause swelling and pain in the elbow joint. A less common cause of swelling in the elbow is infection, either of the skin around the elbow or within the joint itself.