Some causes of swelling in the arm include overuse, osteoarthritis and hormone changes, according to WebMD. Most of the causes of swelling in the arm can heal with home treatment without doctor intervention.
Over using the arm or using repetitive motion may cause an arm to swell, explains WebMD. This motion can cause stress on the tissues of the arm and cause pain in addition to swelling. Some overuse injuries include tendinitis, bursitis and carpal tunnel syndrome. Arthritis in the arm is another cause of swelling in the arm, and it may also cause joint pain and stiffness. The most common type of arthritis is osteoarthritis, but lupus and rheumatoid arthritis may also cause arm swelling.
Women may also experience swelling in the arms due to hormonal changes during pregnancy or if experiencing premenstrual syndrome, states WebMD. It is also possible that swelling in the arms, referred to as lymphedema, may occur following surgery to remove lymph nodes, which is usually done following a diagnosis of melanoma or breast cancer. Older adults are more prone to arm pain and swelling because muscle tends to degenerate over time, and children are prone to swelling and pain in the arms because they tend to be more active than adults.