Final answer:
Metabolic acidosis is indicated by a low pH and low bicarbonate levels in the blood, due to primary bicarbonate deficiency and sometimes followed by decreased pCO2 as a compensatory mechanism.
Step-by-step explanation:
Metabolic acidosis is characterized by physiological changes such as a low pH (below 7.35) and a low bicarbonate (HCO3-) level, indicating primary bicarbonate deficiency. The reduction in bicarbonate is typically due to an increase in acid within the body or an excessive loss of bicarbonate through the gastrointestinal tract. Initially, the carbon dioxide partial pressure (pCO2) may be normal, but as compensatory mechanisms activate, it tends to decrease, aiding the body in bringing the pH back towards normal.
Conditions such as strenuous exercise, ingestion of substances like aspirin, or ketone bodies in diabetic ketoacidosis can cause metabolic acidosis. Lab tests measuring pH, pCO2, and HCO3- can diagnose the condition and determine the extent of compensation by the body's respiratory system, typically via the lungs, as a response to the kidney-related metabolic imbalance.