**Study Overview:** Sickle cell disease (SCD) is a genetic disorder causing intense and ongoing pain for many of the 100,000 affected people in the U.S. The study aims to discover factors that predict severe pain in SCD patients, helping to improve pain management and explore non-opioid treatments. Participants will first join a virtual session answering surveys about their pain and then attend an in-person visit for tests to see how their bodies handle pain. Every three months, they'll receive short surveys via text or electronic medical records about their pain experiences. The study could last up to 48 months for those who start at the beginning. **Key Points:** - **Length of Study:** Up to 48 months, with regular surveys every three months. - **Visits Needed:** One virtual and one in-person initial visit. - **Eligibility:** Must be 15-40 years old with diagnosed sickle cell disease and a history of pain episodes treated with opioids.