Modern sensing technologies are highly required for health monitoring. In this respect, the development of small‐size, high‐performance, and self‐powered biosensors for detecting and quantifying disease markers in biofluids can bring crucial changes and improvements to the concept of health monitoring systems. Clinical trials identify a wide range of biomarkers in biofluids that provide significant health information. Research into novel functional materials with outstanding properties opens up new perspectives for fabricating new‐generation biosensors. Furthermore, energy conversion and storage units are investigated to integrate them into biosensors and develop self‐powered systems. Electrochemical methods are very attractive for applications in biosensor technology, both in terms of biomarker detection and energy generation. Here the recent achievements in research into self‐powered electrochemical biosensors to detect sweat and saliva biomarkers are presented. Potential biomarkers for efficient analysis of these fluids are discussed in light of their importance in identifying various diseases. The influence of electrode materials on the performance of sensors is discussed. Progress in developing operating strategies for self‐powered electrochemical monitoring systems is also discussed. A summary and outlook are presented, mentioning major achievements and current issues to be explored.