I'm not okay.

I don't know what's going on.

I've never had this happen before,

and I don't know where to go and what to do.

I said, Michelle's having a serious problem.

You have to get over there.

You need to go now.

This is an invisible illness, and that's what I think makes it so

difficult because they come in and they have all these complaints, but they look fine. I was standing in the

mirror, and I just remember looking at myself, and I said out loud, there's no way you're going to make it through this.

How terrifying would it be to fight an unknown

enemy? One you didn't recognize and didn't see coming. What if that enemy was coming from within,

a disease that even doctors couldn't identify. Nearly half of Americans suffer from some

chronic illness and many struggle for an accurate diagnosis.

These are their stories.

I'm Lauren Bright Pacheco, and this is symptomatic.

I am Michelle Shapiro, and I'm an integrative and functional registered dietitian.

Michelle is the kind of person who never meets a stranger. She speaks with enthusiasm, confidence,

and is undeniably a New Yorker. So you grew up at Queens. Tell me a little bit about your childhood and life growing up.

I grew up in one of the most diverse neighborhoods in the entire world. I think my high school was the

most diverse high school in the entire world at one point. And because of that, I had such a rich

experience in life in just about every way. Socially, I had a really beautiful life. I had such a rich experience in life in just about every way.

...