Swelling of the elbow is mainly due to inflammatory processes. Excessive fluid collects in the tissue spaces and any cavities in the elbow and causes soft swelling of the area. Sometimes it can involve the bone – bony swelling – although the bone is in most cases resistant to the inflammatory processes affecting the surrounding soft tissue. There are several possible causes of elbow swelling. Swelling at the back of the elbow usually involves the bones, joints or bursa. Swelling on the front of the elbow (brachial fossa) is more likely to be associated with the soft tissue, particularly muscles and its tendons, ligaments, blood vessels, subcutaneous tissue and skin. If the swelling is due to inflammation then there may be other features such as redness of the skin, warmth of the area and elbow pain.