Hench started his career at Mayo Clinic in 1923. He worked in the Department of Rheumatic Diseases. In 1926, he became the head of the department. While at Mayo Clinic, Hench worked mainly on arthritic diseases. This lead him to believe that steroids lessened the pain caused by the disease. During this time, biochemist Edward Calvin Kendall has found several steroids created by the adrenal gland cortex. After several years of work, Hench and Kendall decided to use one of these steroids on patients with rheumatoid arthritis. Testing of the hypothesis was delayed because the synthesis of Compound E was costly and time-consuming, and Hench served in the military during World War II. The tests were conducted successfully in 1948 and 1949. The steroid they used was named Compound E at the time. It later become known as cortisone.