Clinical trials are research studies in which people volunteer to test new drugs or medical devices. Doctors use clinical trials to learn whether a new treatment works and is safe. These kinds of studies are needed to develop new treatments for serious medical problems, such as lung disease. Clinical trials can offer benefits to those who participate. These benefits may include access to new treatment options or medical devices that are not widely available yet. Clinical trials can also give participants a feeling that they are helping to advance medical science. There are different types of clinical trials and they are conducted in progressive phases (from stage I through IV). Once a clinical trial reaches its end and proves that a therapy works, the U.S. Food and Drug Administration (FDA) must still approve that therapy for the public. Participation in a clinical trial is 100% voluntary. If you meet the requirements for one, you will get to decide if you want to take part in it. Talk to your doctor about whether a clinical trial may be right for you. You can also learn more about clinical trials at clinicaltrials.gov.