“I’m tired and sleepy every day,” said the exhausted patient. No matter how early she went to bed or how late she slept, she still felt extremely tired and fatigued. She lacked the energy and mental clarity to do the things she loved to do. Sometimes she’d take naps at work, or worry about falling asleep behind the wheel driving home or picking up her kids from school. After weeks or months of this excessive fatigue, she went to see a sleep medicine specialist to solve the mystery once and for all: why was she so tired all the time?