Distal renal tubular acidosis
Distal renal tubular acidosis is a disease that occurs when the kidneys do not properly remove acids from the blood into the urine. As a result, too much acid remains in the blood (called acidosis).
Renal tubular acidosis - distal; Renal tubular acidosis type I; Type I RTA; RTA - distal; Classical RTA
When the body performs its normal functions, it produces acid. If this acid is not removed or neutralized, the blood becomes too acidic. This can lead to electrolyte imbalances in the blood. It can also cause problems with normal function of some cells.
The kidneys help control the body's acid level by removing acid from the blood and excreting it into the urine.
Distal renal tubular acidosis (Type I RTA) is caused by a defect in the kidney tubes that causes acid to build up in the blood.
Type I RTA is caused by a variety of conditions, including:
- Fabry disease (abnormal buildup in the body of a certain type of fatty substance)
- High blood calcium
- Sickle cell disease
- Sjogren syndrome
- Systemic lupus erythematosus
- Wilson disease
- Use of certain medicines, such as amphotericin B, lithium, and analgesics
Symptoms of distal renal tubular acidosis include any of the following:
- Confusion or decreased alertness
- Impaired growth
- Increased breathing rate
- Kidney stones
- Muscle weakness
Other symptoms can include:
- Bone pain
- Decreased urine output
- Increased heart rate or irregular heartbeat
- Muscle cramps
- Pain in the back, flank, or abdomen
- Skeletal abnormalities
Exams and Tests
The doctor will perform a physical exam and ask about your symptoms.
Tests that may be ordered include:
The goal is to restore normal acid level and electrolyte balance in the body. This will help correct bone disorders and reduce calcium buildup in the kidneys (nephrocalcinosis) and kidney stones.
The underlying cause of distal renal tubular acidosis should be corrected if it can be identified.
Medicines that may be prescribed include potassium citrate and sodium bicarbonate. These are alkaline medicines that help correct the acidic condition of the body. Sodium bicarbonate may correct the loss of potassium and calcium.
The disorder must be treated to reduce its effects and complications, which can be permanent or life-threatening. Most cases get better with treatment.
Untreated, distal renal tubular acidosis can lead to any of the following conditions:
- Kidney stones
- Electrolyte imbalances, such as low blood potassium level
When to Contact a Medical Professional
Call your health care provider if you have symptoms of distal renal tubular acidosis.
Get medical help right away if you develop emergency symptoms, such as:
There is no prevention for this disorder.
DuBose TD Jr. Disorders of acid-base balance. In: Taal MW, Chertow GM, Marsden PA, et al., eds. Brenner and Rector's The Kidney. 9th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 16.
Seifter JL. Acid-base disorders. In: Goldman L, Schafer AI, eds. Goldman'sCecil Medicine. 24th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 120.
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.