The article discusses the importance of acid-base balance in life, the physiological processes necessary for its maintenance, and the role of buffer systems in the body. The pH value of acid and base solutions can change over time due to the absorption of various gases from the air or substances dissolving from the container walls. In the human body, the concentration of hydrogen ions exhibits isohydria, remaining in a highly balanced state. The importance of buffer systems in maintaining the acid-base balance cannot be overstated. Buffers allow for the maintenance of hydrogen ion concentration without significant changes when acid or alkali is added. The article focuses on three main categories of buffer systems: weak acids and their salts, weak bases and their salts, and salts of polyprotic acids. Furthermore, the article discusses the disturbance of acid-base balance in the body (acidosis and alkalosis) and classifies these conditions into respiratory (gaseous) and metabolic (non-gaseous) forms.