Topamax®, developed to treat epilepsy, is also used as a preventative for migraine. In this case study, students read about a woman experiencing a side-effect of Topamax and from there move to a review of acid-base balance in the human body. The case study questions force the students to think about basic concepts related to buffers, pH, and equilibria, and challenge them to make specific connections. The case has two versions: one for chemists/biochemists and a second for physiologists. This is the biochemistry version.  Both versions cover acid-base balance to a similar extent, with the physiology version (titled "One Headache After Another: Physiology Edition") covering more of the factors involved with metabolic acidosis and exercise physiology. Both versions are geared to upper-level undergraduates.