RecruitingClinical and Scientific Assessment of Pain and Painful DisordersBackground: Researchers want to better understand pain by studying people with and without different kinds of pain. To do this, researchers will expose people to pleasant and unpleasant sensations. They will ask them questions about their pain. Researchers also want to see if these people are eligible for other research studies at the National Center for Complementary and Integrative Health. Objectives: To study the experience of pain. Also to find people eligible to join other NIH studies. Eligibility: People 12 years and older with and without pain disorders. Design: Participants will be screened by phone. Participants will have one required visit lasting about 2 hours. This may include: * Medical history * Physical exam * Questionnaires about themselves and their pain experience * Blood and urine tests * MRI: They will lie on a table that slides into a cylinder. They will feel different sensations while completing tasks on a computer. This lasts 15 minutes to 2 hours. * Quantitative sensory testing: They will be exposed to different pictures, sounds, tastes, and smells. They will also be exposed to pleasant and unpleasant sensations. These could include: * Burning, itching, or cold sensations * Pinpricks * Pressure and pinches * Electrocardiogram: Stickers on the chest record heart activity. * Straps placed around the chest to measure breathing. * Small sensors on the fingers or palms to measure pulse and sweating. Participants may have up to 12 other outpatient study visits. Participants may be recorded at the visits.