Back when he was 17 and in high school, Eric Sid fainted. In the emergency room, he was diagnosed with anemia, which can cause fainting spells, and for years he thought that was the end of the story. About a decade later, in the early 2010s, he came down with pneumonia and had blood work done. He took a peek at the results and saw markers of anemia, as he expected. But the report also mentioned that his red blood cells were smaller than normal. Sid was in medical school at the time, and he