Final answer:
Hyperventilation causes respiratory alkalosis by decreasing blood CO2 levels, which leads to fewer hydrogen ions and a more alkaline blood pH, affecting the oxygen-hemoglobin affinity.
Step-by-step explanation:
When a person hyperventilates, the increased ventilation rate leads to abnormally low blood carbon dioxide levels and a higher (alkaline) blood pH, a condition called respiratory alkalosis. This happens because carbon dioxide (CO2) in the blood reacts with water to form carbonic acid, which dissociates into hydrogen ions (H+) and bicarbonate (HCO3-). Lower CO2 levels lead to fewer hydrogen ions, making the blood more alkaline. Consequently, the affinity of hemoglobin for oxygen increases, and the oxygen dissociation curve shifts to the left, meaning oxygen is more tightly bound to hemoglobin. Extended hyperventilation can disrupt the acid-base balance necessary for proper physiological function. The body strives to maintain pH balance through the renal system, which can compensate by adjusting the excretion of acids and bases.