Social Security is adopting revised Listings used in determining disability in children for growth disorders and weight loss. This includes one of the more interesting names for a medical condition, "failure to thrive." Children are expected to thrive, that is to rapidly gain weight and height. "Failure to thrive" is an ominous condition and a challenge for a pediatrician's diagnostic skills. When they can't figure out what the specific problem is or how to cure it, disability can result.