I drove myself to the emergency room in a sheer panic because I was worried if I called the ambulance, you know, they wouldn't get there in time.

He was having chest pains, he felt out of breath, he was feeling shaky, and that was the first

time I really remember that he couldn't do something that we used to love doing together.

So there is no medication.

Some people can have pretty mild symptoms

and other folks can, you know, unfortunately, die.

Frankly, that was incredibly depressing.

I'm dying here.

Let's figure something else out.

Let's try something else because I have no life here.

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 all Americans. but even doctors couldn't identify.

Nearly half of all 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. Whether he's kayaking, backpacking, hiking, or just working out in the garden,

Chris Rose feels most at home while outdoors, where he can breathe fresh air and take in the scenery around him.

He's also developed a passion for capturing his adventures with a camera.

I dabble in photography as a hobby,

...