There may be good reasons for a second degree in the medical field. For example, if you are not happy in your current job and would like to make a fresh start. Or as an additional qualification to an already existing degree.
However, one should also be aware of the risks before making such a decision. First of all, it is important to keep in mind that studying medicine will take a few years and requires intensive study. You should plan on at least six years until you have the state examination in your pocket (the degree "diplomomediziner" no longer exists), and if you are aiming for a doctorate, it can take even longer.