Clinical studies advance modern medicine. They open the door to innovative new diagnostic and treatment options, furthering our understanding of our health and how we can fight and prevent disease. The U.S. National Library of Medicine reports that there are nearly 298,000 registered studies underway in 209 countries, each seeking to answer two basic questions: Does a new treatment work? And, is it safe? But if you're wondering what happens during clinical research trials, you're not alone. Learning more about these types of studies helps you better understand just how instrumental clinical research is to creating life-saving technologies, including new medical products and medications. And once you're informed, you just might decide to participate in clinical research yourself. Wait, What's the Difference? Though all clinical research is conducted on people, the U.S. National Library of Medicine splits clinical studies into two main types: clinical trials (which are also called interventional studies) and observational studies. Observational studies, sometimes referred to as research studies, are exactly what they sound like: Researchers observe people in normal settings, gather information and see what happens over time. Sometimes participants are prescribed drugs, devices or procedures. A clinical trial, on the other hand, investigates a specific intervention — a new medicine, medical device or a new procedure or even a change to a participant's behavior (a change in a person's diet, for example) — to find out the intervention is safe and effective. Sometimes these are brand-new products or approaches; sometimes they compare already-existing treatments. Why Are Clinical Studies Important? Studies and trials are important, the National Institutes of Health (NIH) asserts, because they expand our knowledge of medical science. They give researchers insights into the safety and efficacy of treatments and procedures. They teach medical professionals new things about how diseases work, how we can improve patient health and what types of technologies may be useful for keeping people safe and healthy. Modern medicine wouldn't be possible without clinical research and the people who participate in it, and clinical research is still a critical tool for finding answers to the questions that still vex us. What Does the Research Process Look Like? Every clinical study begins as an idea. Through the clinical research process, doctors and scientists seek to answer questions such as: Are there better ways to diagnose diseases? Can we find new treatments that are more effective than older therapies? How can we prevent diseases? As the clinical trial process begins, these questions are incorporated into a general plan, or protocol, for the study. The protocol, says the U.S. National Library of Medicine, defines the scope of the study, how it will be conducted and why it's necessary. In the United States, organizations called institutional review boards (IRBs) review study protocols, informed consent documents and approve the research. IRBs also monitor the study once it's underway to ensure that the research team adheres to the protocol, protects the participants of the study and acts ethically. What Are the Trial Phases? Clinical trials generally follow the same series of steps as research is completed and results are analyzed. The NIH explains that each phase of the research has a different purpose and helps researchers answer certain questions: Phase 1: An intervention — such as a new drug or device, technology or treatment — is tested on a small group. Researchers pay particular attention to the safety of the new intervention and watch out for any side effects that trial participants experience. Phase 2: The intervention is given to a slightly larger group to further determine its efficacy. Phase 3: A larger group receives the intervention. The information gathered during this phase is used to evaluate the safety of the intervention and compare it to other treatments and technologies. If the intervention is determined to be safe and effective, it's submitted to the United States Food and Drug Administration (FDA) for approval. Phase 4: Once the intervention receives FDA approval, it's made available to the general public. From here, researchers track its safety and learn more about its benefits and where it's best used. Should You Participate? People participate in clinical research trials for a number of reasons, the NIH says. Some people with certain illnesses or diseases want to help researchers understand their maladies; as a bonus, they can sometimes receive cutting-edge treatments and additional care from the clinical trial staff. Healthy people volunteer for clinical trials, too, with an interest in moving science forward and furthering the capabilities of medical technologies for greater global benefit. Not everyone can participate in every trial, though. The U.S. National Library of Medicine notes that every clinical study lists in its protocol eligibility criteria, which determine who can and can't participate in the trial. These criteria are often based on potential participants' age, gender and medical history. There are risks associated with participating in clinical research, too. For most clinical trials, the most severe potential hazard is minor discomfort, the NIH says, but it also notes that some studies come with the risk of serious or even life-threatening side effects. Any risks posed by a trial will be disclosed in what's called an informed consent document, which participants are required to sign and which a member of the research team will explain. The research team can also answer any questions about the study; if you're thinking about participating in one and have concerns, you should raise them. Whatever your reason might be, if you choose to participate in a clinical study, you'll be helping to advance our knowledge of the human body and the treatments and technologies that can help us live better, healthier lives.