Cellular physiology investigates how cells function, adapt, and maintain homeostasis, forming the foundation of all biological processes. It encompasses mechanisms like ion transport, energy production, and signal transduction. This book provides an in-depth understanding of cellular mechanisms, explaining how cells respond to internal and external stimuli. It bridges basic cellular biology with clinical applications, highlighting conditions like ion channelopathies and cellular dysfunction in diseases. Aimed at students and clinicians, it uses diagrams and case studies to link molecular events to physiological outcomes.