The kidneys function as the primary site for maintaining chemical balance in the body. The maintenance of a normal acid-base balance occurs within minute kidney structures termed the renal tubules. Renal tubule malfunction that leads to excessive acid in the blood is termed renal tubular acidosis. The symptoms of renal tubular acidosis relate to the effects of excessive body acid and related chemical imbalances that occur throughout the body.
Altered Breathing Pattern
The Merck Manual for Healthcare Professionals reports that the increased blood acidity associated with renal tubular acidosis can cause an altered breathing pattern characterized by unusually long, deep breaths. The change in breathing facilitates increased elimination of carbon dioxide from the blood. Because carbon dioxide contributes to the acidity of the blood, increased expulsion helps reduce the acid load within the body.
Decreased Urine Output and Dry Mouth
Renal tubular acidosis may cause dehydration, as noted in information provided by Penn State College of Medicine's Milton S. Hershey Medical Center. The deficit in total body water typically leads to decreased urine output, dry mouth and decreased tear production. Among infants and young children, a noticeable lack of skin elasticity and fullness may occur.
Confusion and Impaired Alertness
Acid overload, or acidosis, can adversely affect brain function. In a MedlinePlus entry, Dr. David Dugdale III notes that acidosis may cause mental confusion. A decreased level of alertness may also occur, characterized by sluggishness and inactivity.
Bone Pain and Fragility
Information provided by Penn State College of Medicine's Milton S. Hershey Medical Center notes that certain types of renal tubular acidosis interfere with calcium and phosphate metabolism, leading to poorly mineralized, weak bones. Bone pain may occur along with an increased risk for bone fracture. The effects of impaired bone mineralization are most pronounced in infants and young children. Affected youngsters may exhibit defective tooth formation, stunted growth, a misshapen skull, bowlegs, rib cage deformities and abnormal spine curvature. The term renal rickets describes the bone manifestations associated with renal tubular acidosis in young children.
Weakness and Fatigue
Dr. David Dugdale III notes in MedlinePlus entries on proximal and distal renal tubular acidosis that fatigue and weakness may characterize these disorders. Normal muscle function depends on tightly maintained levels of sodium and potassium within the muscle cells and in the environment surrounding these cells. Excessive acid can disturb these balances, causing muscle weakness and fatigue. Among infants with renal tubular acidosis, muscle weakness may present as an overall lack of muscle tone.
Abnormal Heart Rhythm
One form of renal tubular acidosis, type 4, causes abnormally elevated levels of blood potassium along with the high acid levels. The Merck Manual for Healthcare Professionals explains that patients with an elevated blood potassium may develop heart rhythm abnormalities. A racing or irregular heart rate may compromise heart function.
References
- National Institute of Diabetes and Digestive and Kidney Diseases: Renal Tubular Acidosis
- MedlinePlus: Proximal Renal Tubular Acidosis
- MedlinePlus: Distal Renal Tubular Acidosis
- Merck Manual for Healthcare Professionals: Renal Tubular Acidosis (RTA)
- Merck Manual for Healthcare Professionals: Metabolic Acidosis, Signs and Symptoms
