It develops from the inflammation, compression or entrapment of the ulnar nerve and frequently manifests in the elbow and the wrist. The condition is caused by a variety of factors, including blunt trauma, cysts, and illnesses such as rheumatoid arthritis, diabetes and hemophilia.
Symptoms can appear and progress slowly, often leading to a diagnosis in middle or older age. Men have a greater tendency toward ulnar neuropathy, as do individuals who operate computers for long periods and lean on their elbows for extended stretches (like receptionists and phone operators). Among the risk factors are alcoholism, HIV and a family history of diabetes.