For more than two decades, Sue Harootunian, 47, waged a losing battle against anorexia. Slowly starving herself to death, she avoided eating in front of her family and began jogging obsessively.
Eventually, her 5-foot 4-inch frame wasted away to a mere 80 pounds -- so fragile that death was a real possibility.
"If you look at her physical condition, you're amazed that she can function as well as she does right now, because it's just devastated her physically," said her husband, Lee.
Literally at her breaking point, Harootunian finally sought help at the Renfrew Center, an elite treatment facility in Philadelphia.
She also allowed "20/20" to chronicle her desperate fight to overcome her disease to serve as an example for other women struggling with eating disorders.
"The whole idea of gaining weight is scary, but it's not. I have mixed emotions about it," Harootunian, a mother of three, said on the morning she checked in at Renfrew.
The image of a grown woman struggling with an eating disorder may seem incongruous, but in recent years, experts have detected a hidden epidemic raging in homes all across America, with mothers struggling to save the lives -- not of their daughters -- but of themselves.
Harootunian's anorexia was born out of years of suffering in silence and isolation, and many adult women may find her story unsettling for its ordinary beginnings.
Harootunian's husband, Lee, was an executive at a Fortune 500 company. Because he spent long hours on the road, Harootunian often found herself raising their kids alone, becoming lost in her loneliness.
"I had a difficult relationship with my husband, and I just internalized a lot of things, and I didn't feel pretty. I didn't feel good about myself," she said.
"I probably did neglect some of her needs at the time," her husband said. "If that contributed to this, certainly I'll take responsibility for it."
Feeling that her life was spinning out of control, Harootunian asserted control over the one thing she could -- her body. At times, she ate only popcorn during her meals. She also began drinking heavily and abusing laxatives.
Eventually, Harootunian was so debilitated by her anorexia that she became withdrawn and emotionally unavailable to her family.
"She used to sleep in bed all the time," said her daughter, Kristen, 10. "She'd get too skinny and it would freak me out."
"At least once or twice a day we would notice that mom was sick," said her oldest child, Corbin, 13. "But I had known that it was an eating disorder that we have to take care of so we can get her better."
When Harootunian first arrived at Renfrew, the staff spent several days just trying to stabilize her health.
"She was 67 percent of her ideal body weight. Her heart rate was low. She was dehydrated. She needed to be placed on bed rest," said Dr. Susan Ice, the medical director at Renfrew, where more than 20 percent of patients are women over 35 years old.
"Being very selective about the types of food that one eats; being very preoccupied with weight, leaving the dinner table early -- all those things would sort of signal that there's a problem," Ice said.
Many adults afflicted by eating disorders first developed their illnesses when they were teenagers. Harootunian's case is rare in that hers developed during adulthood.