Transient pseudohypoaldosteronism is a renal tubulopathy characterized by renal tubular resistance to aldosterone, characterized by hyponatremia, metabolic acidosis and hyperkalemia and manifesting as dehydration, secondary to urinary tract malformation and infections in infants.

Abnormal (retrograde) movement of urine from the bladder into ureters or kidneys related to inadequacy of the valvular mechanism at the ureterovesicular junction or other causes.