This study is a screening evaluation for volunteers who are interested in participating in National Center for Complementary and Integrative Health (NCCIH) research studies about pain and related processes, such as emotion, mood, and decision-making. Screening may include review of medical history, physical exam, vital signs, questionnaires, blood and urine tests, and optional sensory testing to better understand pain and related symptoms. The purpose is to identify and characterize healthy volunteers and people with pain who may be eligible for future NCCIH research studies. This screening study does not test a treatment and has no formal hypothesis.