Background: Sickle Cell Disease (SCD) causes blood cells form a crescent shape. It is caused by a genetic mutation in the hemoglobin gene. People with SCD are at increased risk for illnesses like stroke, chronic pain, and heart problems, as well as decreased overall health and well-being. Researchers want to learn more about how nutrition and diet can help relieve or reduce the symptoms of SCD.

Objective: To understand how diet, dietary patterns and behaviors, nutrition, and other related factors in adults with SCD affect their overall health.

Eligibility: Adults aged 18 and older with SCD.

Design: Participants will be screened with a review of their medical records. They will take a pregnancy test if needed. Participants will have a physical exam and medical history. Their height, weight, and waist and hip circumference will be measured. They can complete this exam (1) via telehealth along with a visit to an outpatient laboratory center or (2) by going to the NIH Clinical Center. Participants will complete 2 interviews about their diet. They will talk about the foods they ate in the past 24 hours. They will also complete 1 interview about diet-related behaviors such as food shopping and cooking. They can complete the interviews in person, by phone, or by telehealth visit. Participants will complete surveys about their demographics (such as age and gender), SCD pain, mood, stress, diet, and nutrition. It may take about 1 hour to complete all of the surveys. Participants will give blood and urine samples. They will need to fast for at least 8 hours overnight before giving blood samples. Participation will last for about 2 weeks.