I would say what lead to my diagnosis was years of searching for the reason behind my weakness in my muscles and the weird pain I was experiencing in my head and back, and legs. I saw many neurologists until I was sick to death of the lot of them. Most were rude and made fun of me. Finally I was sent to a rheumatologist, at Cleveland Clinic, who diagnosised me with fibro. However, other doctors disagreed and said it was nothing. Finally I saw another rheumatologist and he reconfirmed the fibro. So a long list of doctors lead me to my final diagnosis.
If you mean't what symptoms, it was pain and numbness, sight problems and odd feelings, weakness in my legs and hands, and arms. Being tired all the time and sometimes being to weak to move. I thought I had MS, but it was fibro in the end.
By the way welcome to the forum.