In metabolic acidosis, the arterial pH is typically:

• A. High
• B. Low
• C. Normal
• D. Variable

Answer: (B)

When metabolic acidosis occurs, there is an excess of hydrogen ions or a loss of bicarbonate, which shifts the body's acid-base balance toward acidity. That increase in acidity lowers the arterial pH, producing acidemia (pH below the normal ~7.35–7.45 range). The respiratory system tries to compensate by blowing off carbon dioxide through faster breathing, which can raise pH toward normal, but the pH is typically still below normal in metabolic acidosis unless compensation is complete. So the most consistent pattern is a low arterial pH. High pH would indicate alkalosis, a normal pH suggests no acid-base disturbance or a mixed disorder, and a variable pH would imply inconsistent findings or mixed processes.