Amyotrophic lateral sclerosis (ALS), sometimes called Lou Gehrig's disease, is a progressive disease that attacks the nerve cells that control voluntary movement. The National ALS Registry is a congressionally mandated registry for persons in the U.S. with ALS. It is the only population-based registry in the U.S. that collects information to help scientists learn more about who gets ALS and its causes. No one knows for sure what causes ALS and currently there is no cure. If you have the disease, consider joining the Registry and completing the brief risk-factor surveys because your answers could help scientists defeat ALS.