distal renal tubular acidosis (RTA), an abnormal condition characterized by excessive acid accumulation and bicarbonate excretion. It is caused by the inability of the kidney’s distal tubules to secrete hydrogen ions, thus decreasing the excretion of titratable acids and ammonium and increasing the urinary loss of potassium and bicarbonate. The condition may cause hypercalciuria and the formation of kidney stones. Treatment is the same as for renal tubular acidosis. Primary distal RTA occurs mostly in females, adolescents, older children, and young adults. It may occur sporadically or result from hereditary defects. Secondary distal RTA is associated with numerous disorders, such as cirrhosis of the liver, malnutrition, starvation, and various genetic abnormalities. Compare primary proximal RTA, proximal renal tubular acidosis.
