Chapter 5 is an intensive look at the phenomenon of nervos, a term for a collection of ambiguous physical and mental conditions that affect the residents of the Alto, and greater Northwest Brazil. The precise idea of nervos is unclear: the residents use the term to describe a wide range of condition and discomforts, from headaches, to nausea, to fainting spells, bad dreams, difficulty eating or drinking, and general malaise. The author argues initially that nervos is an expression of their chronic "hunger"―that is, both a symptom of their chronic malnutrition and a sense of their repression within the exploitative system of sugarcane cultivation and processing.

However, the account of the author’s recollections and interactions with residents of the Alto complicate this notion: while the residents understand that their symptoms are in part caused by the pain, anxiety, and frustration of their lives, the full account of nervos is greater than that; the residents distinguish readily between nervos caused by hunger and nervos caused by a humiliating interaction with a boss, and so on. Nervos, then, represents a set of social behaviors connected to, and influenced by, the impoverished life of the Alto. To wit, the author's interactions with sufferers of nervos typically include an inconclusive or fruitless contact with a modern medical professional, who cannot find a workable diagnosis for these symptoms.