Which type of acid-base disturbance is primarily caused by renal failure?

Renal failure leads to an accumulation of acids in the body because the kidneys are unable to excrete hydrogen ions and maintain proper bicarbonate levels. This results in a decreased ability to excrete metabolic acids such as sulfate, phosphate, and urea. Consequently, the blood becomes more acidic, which is characterized as metabolic acidosis.

In a healthy individual, the kidneys play a crucial role in maintaining acid-base balance by regulating the excretion of hydrogen ions and reabsorbing bicarbonate. When renal function declines, these processes are impaired, leading to an increase in endogenous acid production and a reduction in bicarbonate reabsorption. This shift in balance ultimately results in metabolic acidosis, identifiable by a decreased blood pH and a low bicarbonate concentration.

Understanding this mechanism is essential, as other types of acid-base disturbances, such as metabolic alkalosis, respiratory alkalosis, and respiratory acidosis, arise from different physiological processes unrelated to renal impairment.