The health status of individual fish can provide vital information on potential causes of changes in fish populations in response to natural and anthropogenic stressors. Disturbance can cause declines in individual fish health and consequently affect reproductive output with potential implications for population persistence. Fish health is a broadly used term, commonly encompassing assessments of energetic status (condition) as well as other underlying physiological functions that can be considered as components of overall fish health. While there have been previous reviews of particular health components and how they are measured, there is a need for review and synthesis of fish health assessment methods that can be used as rapid indicators of fish health, while providing a mechanistic understanding of the interaction between environmental stressors and fish health. This talk presents the results of a systematic literature review and topic modelling study based on a corpus of 1430 papers. The literature review: (1) summarises current methods for assessing different components of fish health, 2) identifies key research themes and knowledge gaps, and (3) summarises potential mechanistic links between various components of fish health and key environmental stressors. A decision tree is also presented to assist future researchers in choosing the most appropriate methods to meet particular study objectives and improve management interventions.