Bipolar disorder is among the top 10 causes of disability worldwide. It is managed through a combination of medical and psychotherapeutic interventions, but finding an effective treatment is often a long process of trial-and-error, that medical professionals and people diagnosed with this condition engage upon. This article investigates how people diagnosed with bipolar disorder enact lay expertise about the treatment of this condition online. Using De Certeau’s (1988) theory of everyday practices, three tactics are identified—complexity, uncertainty, and individualization—through which people diagnosed creatively adapt medical knowledge on bipolar disorder, to render their personal experiences and views on treatment more authoritative. It is suggested that through their technological features, which allow for the accumulation and refinement of the insights contributors share, blogs may function as digital repositories of patient experiences and may thus help facilitate collective processes of knowledge production. Online data were collected from two blogs, which were selected using the Google index as relevance indicator, and were analyzed through computer-mediated discourse analysis.