This review examines links between extremely low-frequency electromagnetic fields, especially the Schumann resonance at ~7.83 Hz, and biological regulation of bioelectricity. It describes proposed mechanisms involving calcium flux modulation and downstream effects on neural activity (including EEG) and circadian rhythms. The article presents both potential benefits from controlled ELF exposures (e.g., therapeutic applications) and potential harms from artificial EMFs disrupting key physiological processes, while emphasizing the need for further research.