Long was born in Cleveland, Ohio, the daughter of Andrew and Heloweise Davis Duhart. She graduated from East High School in Cleveland, and in 1973, she received her bachelor's degree in biology from Northwestern University. In 1977, Long received her medical degree from the Saint Louis University School of Medicine followed by residencies at the Cleveland Clinic, Mt. Sinai Hospital in Cleveland, Ohio, and Wright State University in Dayton, Ohio, where she received her Masters of Science degree in aerospace medicine.