Musician David Cassidy; a teen lives in excruciating pain; new parents hire sleep experts to sleep-train their baby; Dr. Jennifer Berman undergoes a minimally invasive neck-lift; a man tours Europe on the backs of friends.

A woman weighing more than 1,100 pounds plans to have weight-loss surgery; a former high-school wrestler says he contracted herpes during a match; whether cell phones should be allowed on airplanes; whether an illness is a cold or something worse.

A young woman who struggled with an eating disorder and cocaine addiction returns to the show; the fitness model who relied on an artificial heart in a backpack; a simple tip to boost mood that doesn't cost a penny.