Woman's lupus journey sheds light on how the body attacks itself in autoimmune diseases

It's one of medicine's biggest mysteries — why sometimes our immune system attacks our own bodies.

Autoimmune diseases affect as many as 50 million Americans and millions more worldwide.

They're hard to diagnose and treat, and they're on the rise.

A Massachusetts woman's journey with one named lupus — called the disease of 1,000 faces for its baffling variety of symptoms — offers a snapshot of the burden.

Now researchers are decoding the biology behind these debilitating diseases in hopes of eventually treating the causes, not just the symptoms.